#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

int main()
{
    int n,m,k;

    int araay[111],array1[111];
    int max=0;
    scanf("%d%d",&n,&k);

    for(int i=0;i<n;i++)
        scanf("%d",&araay[i]);

    for(int i=0;i<k;i++)
    {
        int countinfo=0,countsocial=0;
        for(int j=0;j<n;j++)
        {
            array1[j]=araay[j];
        }
        for(int j=i;j<n;j+=k)
        {
            array1[j]=0;
        }
        for(int j=0;j<n;j++)
        {
            if(array1[j]==1)
                countinfo++;
            else if(array1[j]==-1)
                countsocial++;
        }
        int result=abs(countinfo-countsocial);
        if(result>max)
            max=result;
    }
    printf("%d",max);

}

#include<stdio.h>
#include<math.h>
#include<string.h>
#define Max 100000
int main(){
	int n,k;
	int c,b,i;
	int num[Max];
	int num1[Max];
	int sum1=0,sum2=0,r[Max];
	int j,e,f,a=0;
	int temp=0;
	scanf("%d%d",&n,&k);
	for(j=0;j<n;j++){
		scanf("%d",&num[j]);
	}
	int q=k;

	for(b=q-1;b>=0;b--){

		i=0;
		sum1=0;
		sum2=0;
		c=0;
		for(j=0;j<n;j++){
			num1[j]=num[j];
		}
		while(c<=n){
			c=b+i*k;
			num1[c-1]=0;
			i++;
		}
//		for(j=0;j<n;j++){
//			printf("%d",num1[j]);
//			}
		for(j=0;j<n;j++){
			if(num1[j]==1){
				sum1++;
			}
			if(num1[j]==-1){
				sum2++;
			}
//			printf(" %d%d\n",sum1,sum2);
		}
		int l;
		l=sum1-sum2;
		r[a]=abs(l);
//		printf("    %d       \n",r[a]);
		a++;
	}
	for(e=0;e<a-1;e++)
		for(f=e+1;f<a;f++)
			if(r[e]<r[f])
			{
				temp=r[e];
				r[e]=r[f];
				r[f]=temp;
			}
	printf("%d",r[0]);
	return 0;
}

#include<stdio.h>

int main() {
    int n, k;
    int arr[105];

    scanf("%d %d", &n, &k);
    int cons = 0;
    for(int i =0; i< n; i++) {
        scanf("%d", &arr[i]);
        cons += arr[i];
    }

    int result = 0;

    for(int b= 0; b < n; b++) {
        int temp= cons;
        for(int i = 0; i*k < n; i++) {
            if(b - i*k >= 0) temp -= arr[b - i * k];
            if(b + i*k < n && i != 0) temp -= arr[b + i * k];
        }
        if( temp < 0 ) temp = -1 * temp;
        if( temp > result) result = temp;
    }

    printf("%d", result);

    return 0;
}

#include<stdio.h>

int main()
{
    int n,k,pcount=0,ncount=0,mag,max=0;
    scanf("%d%d",&n,&k);
    int array[n];
    for(int i=0;i<n;i++)
    {
        scanf("%d",&array[i]);
        if(array[i]>0)
        pcount++;
    }
    ncount=n-pcount;
    for(int i=0;i<k;i++)
    {
        int move=i,count=0,t=(n-i-1)/k;
        for(int j=0;j<=t;j++)
        {
            if(array[move]==1)
            count++;
            else
            count--;
            move+=k;
        }
        mag=pcount-ncount-count;
        if(mag<0)
        mag=-mag;

        if(max<mag)
        max=mag;

    }
    printf("%d",max);

}

#include<stdio.h>
#include<math.h>
int main()
{
	int n,q=0,w=0,c;
	int k;
	int a[10000];
	int b[10000],max=-999999;
	scanf("%d %d",&n,&k);
	if(n==1)
	{
		scanf("%d",&c);

		printf("1\n");
		return 0;
	}
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&a[i]);
	}
	for(int b=1;b<=n;b++)
	{	q=0;w=0;
		for(int j=1;j<=n;j++)
		{
			if((j-b)%k==0)

			{continue;

			}
			if(a[j]==1)
			w++;
			else
			q--;
		}
		if(abs(q+w)>max)
		max=abs(q+w);

	}

	printf("%d",max);

	return 0;
}

#include<stdio.h>
#include<math.h>
int main()
{
	int n,q=0,w=0,c;
	int k;
	int a[10000];
	int b[10000],max=-999999;
	scanf("%d %d",&n,&k);
	if(n==1)
	{
		scanf("%d",&c);

		printf("1\n");
		return 0;
	}
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&a[i]);
	}
	for(int b=1;b<=n;b++)
	{	q=0;w=0;
		for(int j=1;j<=n;j++)
		{
			if((j-b)%k==0)

			{continue;

			}
			if(a[j]==1)
			w++;
			else
			q++;
		}
		if(abs(w-q)>max)
		max=abs(w-q);

	}

	printf("%d",max);

	return 0;
}

#include <stdio.h>
int main(void)
{
	int n,k;
	scanf("%d %d",&n,&k);
	int c=0;
	int d=0;
	int ct=0;
	int dt=0;

	int a[n];
	for (int i = 0; i < n; ++i)
	{
		scanf("%d",&a[i]);
		if(a[i]==1) c++;
		else d++;
	}
	int max=0;
	for (int i = 0; i < k; ++i)
	{
		ct=c;
		dt=d;
		for (int j = i; j < n; j+=k)
		{
			if(a[j]==1)
			{
				ct--;
			}
			else
			{
				dt--;
			}
		}
		if(ct-dt>max)
		{
			max=ct-dt;
		}
		else if(dt-ct>max)
		{
			max=dt-ct;
		}
	}
	printf("%d\n",max );
}

#include <stdio.h>
#include <math.h>
int main()
{
    int n,k;
    scanf("%d %d",&n,&k);
    int arr[n];
    for(int i = 0;i<n; i++)
        scanf("%d",&arr[i]);
    //int e,s;
    int ans=0;
    for(int i = 0; i < k; i++)
    {
        int e=0,s=0;
        int temp[n];
        for(int j=0;j<n;j++)
            temp[j]=arr[j];
        for(int j = i; j < n;)
        {
            temp[j]=0;
            j+=k;
        }
        for(int j = 0; j < n; j++)
        {
            if(temp[j]==1)
                e++;
            else if(temp[j]==-1)
                s++;
        }
        if(fabs(e-s)>=ans)
            ans=fabs(e-s);
    }
    printf("%d",ans);
    return 0;
}

#include <stdio.h>
int main()
{
	int n,k;
	scanf("%d %d",&n,&k);
	int a[n];
	for (int i=0;i<n;i++)
		scanf("%d",&a[i]);
	int b[n];
	for (int i=0;i<n;i++)
		b[i]=a[i];
	int max=0;
	for (int i=0;i<n;i++)
	{
		int sum=0;
	   for (int j=i;j<n;j+=k)
		b[j]=0;
	for (int j=i;j>=0;j-=k)
		b[j]=0;
	for (int i=0;i<n;i++)
		sum+=b[i];
	if (sum>max)
		max=sum;
	else if (sum<0 && (sum*(-1))>max)
        max=sum*(-1);
    for (int i=0;i<n;i++)
    	b[i]=a[i];
	}
	printf("%d\n",max);

	return 0;
}

#include<stdio.h>
int A[1000],A1[1000];
int main() {
	int n, k, i, j, t, p, max = 0;
	int plus = 0, minus = 0;
	scanf("%d %d", &n, &k);
	for (i = 0; i < n; i++)
		scanf("%d", &A[i]);
	for (i = 0; i < k; i++) {
		for (j = 0; j < n; j++)
			A1[j] = A[j];
		for (j = i; j < n; j += k)
			A1[j] = 0;
		plus = 0;
		minus = 0;
		for (j = 0; j < n; j++) {
			if (A1[j] == 1)
				plus++;
			else if (A1[j] == -1)
				minus++;
		}
		if(plus>minus)
            p=plus-minus;
        else
            p=minus-plus;
		if (max < p)
			max = p;
	}
	printf("%d", max);

	return 0;
}

#include <stdio.h>
#include <math.h>
#include <string.h>
int main ()
{
    int n,k;
    int i,j;
    int a[100010];
    scanf("%d%d",&n,&k);
    int zheng,fu;
    zheng=fu=0;
    for(i=1;i<=n;i++)
    {
        scanf("%d",&a[i]);
        if(a[i]>0)zheng++;
        else fu++;
    }
    int x=zheng;
    int xx=fu;
    int max=0;
    for(i=1;i<=k;i++)
    {
        zheng=x;
        fu=xx;
        for(j=i;j<=n;j+=k)
        {
            if(a[j]>0)zheng--;
            else fu--;
        }
        if(abs(zheng-fu)>max)max=abs(zheng-fu);
    }
    printf("%d",max);
}

#include<stdio.h>
#include <stdlib.h>

int max(int, int);

int main(){
  int n, k, i, ans;
  scanf("%d %d", &n, &k);
  int array[n - 1];

  for (i = 0; i < n; i++){
    scanf("%d", &array[i]);
  }

  ans = 0;
  for (i = 0; i < k; i++){
    int array_2[n - 1], j;
    // Make a copy of array in array_2
    for (j = 0; j < n; j++){
      array_2[j] = array[j];
    }
    // Mark tabs 0 which are to be skipped
    for (j = i; j < n; j = j + k){
      array_2[j] = 99999;
    }

    int count1 = 0, count2 = 0, q;
    // Get count 1
    for (q = 0; q < n; q++){
      if (array_2[q] == 1)
        count1++;
    }
    // Get count 2
    for (q = 0; q < n; q++){
      if (array_2[q] == -1)
        count2++;
    }
    ans = max(ans, abs(count1 - count2));
  }
  printf("%d\n", ans);

  return 0;
}

int max(int num1, int num2){
  if (num1 > num2)
    return num1;
  else
    return num2;
}

#include <stdio.h>
#include <math.h>

int n,k;
int dem[101];
int main()
{
	int web,i;
	scanf("%d%d",&n,&k);
	for(i=1 ; i<=n ; i++)
	{
		scanf("%d",&web);
		dem[i%k]+=web;
		dem[k]+=web;
	}

	int kq=0;
	for(i=0 ; i<k ; i++)
	{
		dem[i]=abs(dem[k]-dem[i]);
		kq=kq>dem[i]?kq:dem[i];
	}

	printf("%d",kq);
	return 0;
}

#include<stdio.h>
int main(){
   int n , k , j , e = 0 , s=0  , num = 0 , sum , max = 0  ;
   scanf("%d %d",&n , &k) ;
   int i , a[n]   ;
   for(i=0 ; i<=n ; i++){
       scanf(" %d", &a[i])   ;
      // sum += a[i]  ;
   }
for(j=0 ; j<n ; j++){
    e = 0 ;
    s = 0 ;
    for(i=0 ; i<n ; i++){
        int x = j-i ;
        if(x<0) x = -x ;
        if((i==j)||(x%k==0)) continue ;
        else{
            if(a[i]==1) e++ ;
            else s++ ;
        }
    }
   sum = e-s ;
   if(sum<0) sum = -sum ;
   if(max<sum) max = sum ;
}
   printf("%d",max) ;
    return 0 ;
}

#include<stdio.h>
#include<stdlib.h>

int B[3];

int main(void)
{
int n,k,j,A[101],i,count_1,count1,max=-1;

scanf("%d%d",&n,&k);
for(i=1; i<=n; i++)
{
scanf("%d",&A[i]);
B[A[i]+1]++;
}

for(i=1; i<=k; i++)
{
 count_1=B[0];
 count1=B[2];

for(j=i; j<=n; j+=k)
{
    if(A[j]==-1)
     count_1--;
    else
     count1--;
}

if(abs(count_1-count1)>max)
max=abs(count_1-count1);
}

printf("%d",max);
return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef unsigned long long ll;
typedef long double LD;

#define MAXN 100

#define MAX(a,b) (a>b?a:b)

int arr[MAXN];
int arrcpy[MAXN];

int main(void)
{
    int N,K;
    int i,j;
    int B;
    int socialtab,infotab;
    int diff,maxdiff;

	#ifndef ONLINE_JUDGE
    FILE *fp;
	//fp = freopen("..\\..\\1047\\C\\1047C.TXT","r",stdin);
	fp = freopen("1100A.TXT","r",stdin);
	if (fp == NULL)
    {
        printf ("Cannot open file\n\n");
        exit(0);
    }
	#endif

    maxdiff = 0;

    scanf("%d%d",&N,&K);

    for (i=0; i<N; i++)
    {
        scanf("%d",&arr[i]);
    }

    // check for b=0 to k-1
    for (B=0; B<K; B++)
    {
        memcpy(arrcpy, arr, sizeof(arr[0]) *N);

        for (j=B; j<N; j+=K)
        {
            arrcpy[j] = 0;
        }

        // compute ans
        socialtab = 0;
        infotab = 0;
        for (j=0; j<N; j++)
        {
            if (arrcpy[j] == -1)
            {
                socialtab++;
            }
            else if (arrcpy[j] == 1)
            {
                infotab++;
            }
        }
        diff = abs(socialtab - infotab);

        maxdiff = MAX(maxdiff,diff);
    }

    printf ("%d",maxdiff);

    return 0;

}

#include <stdio.h>

int n,k;
int A[110],B[110];
int ab(int a){
    if(a>0)return a;
    return -a;
}
int main(){
   // freopen("input.txt","r",stdin);
    scanf("%d %d",&n,&k);
    int i,j;
    for(i=1;i<=n;i++){
        scanf("%d",&A[i]);
    }
    int mx=0,ans=0,info=0,snt=0;
    for(i=1;i<=k;i++){
        info=0,snt=0;
        for(j=1;j<=n;j++)B[j]=A[j];
        for(j=i;j<=n;j+=k){B[j]=0;}
        for(j=1;j<=n;j++){
            if(B[j]>0)info++;
            if(B[j]<0)snt++;
        }
        ans=ab(info-snt);
        //printf("%d: %d %d %d\n",i,ans,info,snt);
        if(ans>mx){
            mx=ans;
        }
    }
    printf("%d",mx);
}

#include<stdio.h>
#include<math.h>
int main(void)
{
	// your code goes here
	int n,k,i,j,l,e,s,max=-1;
	scanf("%d %d",&n,&k);
	int a[n],b[n];
	for(i=0;i<n;i++)
	{
	    scanf("%d",&a[i]);
	    b[i]=a[i];
	}
	for(i=0;i<k;i++)
	{
	    j=i;
	    e=0;
	    s=0;
	    while(j<=n-1)
	    {
	        b[j]=0;
	        j=j+k;
	    }
	    for(l=0;l<n;l++)
	    {
	        if(b[l]==1)
	          e++;
	        else if(b[l]==-1)
	          s++;
	        b[l]=a[l];
	    }
	    if(max<abs(e-s))
	       max=abs(e-s);
	}
	printf("%d",max);
	return 0;
}

#include <stdio.h>
#include <stdlib.h>

int main(){
  int n, k;
  int a[100];
  int A = 0, B = 0;
  int ans = 0;
  scanf("%d %d", &n, &k);
  for (int i = 0; i < n; i++) scanf("%d", &a[i]);
  for (int i = 0; i < n; i++){
    A = B = 0;
    for (int j = i; j < n; j += k) a[j] += 3;
    for (int j = i - k; j >= 0; j -= k) a[j] += 3;
    for (int j = 0; j < n; j++) A += a[j] == 1, B += a[j] == -1;
    if (abs(A - B) > ans) ans = abs(A - B);
    for (int j = 0; j < n; j++) a[j] -= 3 * (a[j] == 2 || a[j] == 4);
  }
  printf("%d", ans);
  return 0;
}

#include<stdio.h>
#include<math.h>
int Max(int a,int b);
int a[110];
int main(void)
{
    int n,k,max = 0;
    int c=0,d=0;
    int e = 0,s = 0;
    scanf("%d%d",&n,&k);
    for (int i = 1;i<=n;i++){
        scanf("%d",&a[i]);
        if (a[i] == 1) e++;
        else s++;
    }
    for (int i = 1;i<=k;i++){
    	c = d = 0;
        for (int j = i;j <= n;j += k){
            if(a[j] == 1) c++;
            else d++;
        }
        max = Max(max,fabs((e-c)-(s-d)));
    }
    printf("%d\n",max);

    return 0;
}
int Max(int a,int b)
{
	return a>=b?a:b;
}

#include <stdio.h>
#include<math.h>
int n, k, a[105], i,key;
int cul(int key)
{
	int e = 0, s = 0;
	for (i = 1; i <= n; i++)
	{
		if (i%k == key)continue;
		else if (a[i] == 1)s++;
		else e++;
	}
	return abs(e - s);
}
int main()
{
	int max = 0;
	scanf("%d %d", &n, &k);
	for (i = 1; i <= n; i++)
		scanf("%d", &a[i]);
	for (key = 0; key < k; key++)
		if (cul(key) > max)max = cul(key);
	printf("%d", max);
}

#include <stdio.h>
#include <stdlib.h>

/* run this program using the console pauser or add your own getch, system("pause") or input loop */

int main(int argc, char *argv[]) {
	int n,k,i,j,l,o;
	int tab[100]={};
	scanf("%d",&n);
	scanf("%d",&k);
	for(i=0;i<n;i++)
		scanf("%d",&tab[i]);
	int max=0;
	for(i=0;i<k;i++)
	{
		o=0;
		for(j=0;j<n;j++)
		{
			if(j%k-i!=0)
				o+=tab[j];
		}
		//printf("%d-",o);
		if(o>max)
			max=o;
		else if(-o>max)
			max=-o;
	}
	printf("%d\n",max);
	return 0;
}

#include <stdio.h>
#include <stdlib.h>

#define N 100

int main() {
	static int aa[N];
	int n, k, i, sum, max;

	scanf("%d%d", &n, &k);
	sum = 0;
	for (i = 0; i < n; i++) {
		int a;

		scanf("%d", &a);
		aa[i % k] += a;
		sum += a;
	}
	max = 0;
	for (i = 0; i < k; i++)
		if (max < abs(sum - aa[i]))
			max = abs(sum - aa[i]);
	printf("%d\n", max);
	return 0;
}

#include <stdio.h>
#include <string.h>
#include <stdlib.h >

int arr[110];

int main()
{
    int i,j,num,gap,e,s,p,ans,tem;
    scanf("%d%d",&num,&gap);
    for (i=0;i<num;i++)
        scanf("%d",&arr[i]);
    for (j=0,ans=0,tem=0;j<gap;j++)
    {
        for (i=0,e=0,s=0,p=j;i<num;i++)
        {
            if (i!=p)
            {
                if (arr[i]==1)
                    e++;
                else
                    s++;
            }
            else
                p+=gap;
        }
        tem=abs(e-s);
        ans=ans>tem?ans:tem;
    }
    printf("%d\n",ans);
	return 0;
}

#include <stdio.h>

int main(void)
{
    int n,k;
    scanf("%d %d",&n,&k);

    int a[n],b[n];
    for(int i=0;i<n;i++){
        scanf("%d",&a[i]);
        b[i]=a[i];
    }
    int st=0,maxdiff=0;
    for(int i=0;i<n;i++){
        st=i;
        while (st>=0) st-=k;
        st+=k;
        for(int j=st;j<n;j+=k){
            b[j]=0;
        }
        int ij=0,s=0;
        for(int j=0;j<n;j++){
            if(b[j]==-1) s++;
            if(b[j]==1) ij++;
        }
       // printf("%d %d\n",s,ij);
        //for(int q=0;q<n;q++)printf("%d ",b[q]);printf("\n");
        if(s-ij>maxdiff)maxdiff=s-ij;
        else if(ij-s>maxdiff)maxdiff=ij-s;
        for(int l=0;l<n;l++)
            b[l]=a[l];
    }
    printf("%d\n",maxdiff);
}

#include<stdio.h>
int main(){
	int k, n;
	int type[100];
	scanf("%d %d",&n,&k);
	for(int i=0; i<n; i++){
		scanf("%d",&type[i]);
	}
	int max=0;
	for(int i=0; i<k; i++){
		int cnt=0;
		for(int j=0; j<n; j++){
			if(j%k != i) {
				cnt+=type[j];
			}

		}
		if(cnt<0) cnt=-cnt;
		if(max<cnt) max=cnt;
	}
	printf("%d\n",max);
}

#include<stdio.h>
int main()
{
	int k, n;
	int type[100];
	scanf("%d %d",&n,&k);
	for(int i=0; i<n; i++)
	{
		scanf("%d",&type[i]);
	}
	int max=0;
	for(int i=0; i<k; i++)
	{
		int cnt=0;
		for(int j=0; j<n; j++)
		{
			if(j%k != i)
			{
				cnt+=type[j];
			}

		}
		if(cnt<0)
		    cnt=-cnt;
		if(max<cnt)
		    max=cnt;
	}
	printf("%d\n",max);
}

#include <stdio.h>

int main(int argc, char *argv[])
{
    int n, k;
    scanf("%d %d", &n, &k);

    int a[100];
    int i;
    for (i = 0; i < n; i++)
        scanf("%d", &a[i]);

    int max = 0;
    int b;
    for (b = 0; b < k; b++) {
        int a_[100];
        for (i = 0; i < n; i++)
            a_[i] = a[i];

        int c;
        for (c = b; c < n; c += k)
            a_[c] = 0;

        int max_cur = 0;
        for (i = 0; i < n; i++)
            max_cur += a_[i];

        if (max_cur < 0)
            max_cur = -max_cur;

        if (max_cur > max)
            max = max_cur;
    }

    printf("%d\n", max);

    return 0;
}

#include<stdio.h>
#include <stdlib.h>
int main()
{
	long long int n, k;
	scanf("%lld%lld", &n, &k);
	int s[n];
	for (int i = 0; i < n; ++i)
	{
		scanf("%d", &s[i]);
	}
	int max=0;
	for (int i = 0; i < n; ++i)
	{
		int cnt1=0, cnt2=0, temp[n];

		for(int j=0; j<n; j++)
		{
				temp[j]=s[j];
		}
		for(int j=i; j>=0; j-=k)
		{
				temp[j]=0;
		}
		for(int j=i; j<n; j+=k)
		{
			temp[j]=0;
		}
		for(int j=0; j<n; j++)
		{
			if(temp[j]==1)
				cnt1++;
			else if(temp[j]==-1)
				cnt2++;
		}
	//	printf("%d %d\n",cnt1, cnt2 );
		if(abs(cnt1-cnt2)>max)
			max=abs(cnt1-cnt2);
	}
	printf("%d\n", max);

}

#include <stdio.h>
#include <math.h>

int main()
{
	int i,j,n,m;
	int a,b,s,x,y;
	scanf("%d %d",&n,&m);
	int ar[n];
	x=y=0;
	for(i=0;i<n;i++)
	{
		scanf("%d",&ar[i]);
		if(ar[i]>0)x++;
		else y++;
	}
	s=0;
	for(i=0;i<m;i++)
	{
		a=x; b=y;
		for(j=i;j<n;j+=m)
		{
			if(ar[j]>0)a--;
			else b--;
		}
		if(abs(a-b)>s)s=abs(a-b);
	}
	printf("%d\n", s);
	return 0;
}

#include <stdio.h>
int main()
{
    int n,k;
    scanf("%d%d",&n,&k);
    int a[n],i,j,max=0,e=0,s=0;
    for(i=0;i<n;i++)
    scanf("%d",&a[i]);
    for(i=0;i<k;i++)
    {
        e=0;
        s=0;
        for(j=0;j<n;j++)
        {
            if((j-i)%k!=0)
            {
                if(a[j]==1)
                    e++;
                else
                    s++;
            }
        }
        if(e-s>max)
            max=e-s;
        if(s-e>max)
            max=s-e;
    }
    printf("%d",max);
    return 0;
}

#include <stdio.h>

int mod(int a){
    if(a > 0) return a;
    else return -a;
    return -1000;
}

int main(){
    int n, k, b, i, j, eg=0, sg=0;
    scanf("%d %d", &n, &k);
    int arr[n];

    for(i = 0; i < n; i++){
        scanf("%d", &arr[i]);
        if(arr[i] == 1) eg++;
        if(arr[i] == -1)sg++;
    }
    int e=0, s=0, max = 0;
    for(b = 0; b < k; b++){
        e=0;
        s=0;
        for(i = 0; b+i*k < n; i++){
           if(arr[b+i*k] == 1) e++;
           if(arr[b+i*k] == -1)s++;
        }
        if(mod(eg-e-sg+s) > max) max = mod(eg-e-sg+s);
        //printf("%d %d\n", mod(eg-e-sg+s), b);
    }
    printf("%d", max);
    return 0;
}

#include<stdio.h>
#include<stdlib.h>
#include<stdint.h>
#include<inttypes.h>

typedef int64_t i64;
typedef int32_t i32;

static void print_int(i64 n){if(n<0){putchar('-');n=-n;}if(n==0){putchar('0');return;}int s[20],len=0;while(n>0){s[len++]=n%10+'0';n/=10;}while(len>0){putchar(s[--len]);}}
static i64 read_int(void){int prev='\0';int c=getchar();while(!('0'<=c && c<='9')){prev=c;c=getchar();}i64 res=0;while('0'<=c && c<='9'){res=10*res+c-'0';c=getchar();}return prev=='-'?-res:res;}

#define MAX(a,b) ((a)>(b)?(a):(b))
#define ABS(a) ((a)>(0)?(a):-(a))

void run (void) {
  i32 n = read_int();
  i32 k = read_int();
  i32 *cnt = (i32 *) calloc (k, sizeof (i32));
  i32 sum = 0;
  for (i32 i = 0; i < n; ++i) {
    i32 a = read_int();
    cnt[i % k] += a;
    sum += a;
  }
  i32 max = 0;
  for (i32 i = 0; i < k; ++i) {
    max = MAX(max, ABS(sum - cnt[i]));
  }
  print_int (max);
  puts("");
}

int main (void) {
  run ();
  return 0;
}

#include <stdio.h>
#include <stdlib.h>

int main()
{
    int n, k;
    int A[100];
    scanf("%d %d", &n, &k);
    for(int i = 0; i < n; ++i) {
        scanf("%d", &A[i]);
    }
    int ans = 0;
    for(int i = 0; i < k; ++i) {
        int e = 0;
        int s = 0;
        for(int j = 0; j < n; ++j) {
            if((j - i + n) % k != 0) {
                if(A[j] == 1) {
                    ++e;
                } else {
                    ++s;
                }
            }
        }
        if(ans < abs(e - s)) {
            ans = abs(e - s);
        }
    }
    printf("%d", ans);
    return 0;
}

#include <stdio.h>
#include <math.h>
int main()
{
    static int a[101], t, n, k, sum, max ,i;
    scanf("%d%d", &n, &k);
    for(i=0; i<n; i++)
    {
        scanf("%d",&t);
        a[i%k] += t;
        sum += t;
    }
    for(i=0; i<k; i++)
    {
        if(max < abs(sum-a[i]))
            max = abs(sum-a[i]);
    }
    printf("%d\n", max);
    return 0;
}

#include<stdio.h>
int main()
{
	int n,i,t,k;
	int b,e,s;
	scanf("%d %d",&n,&k);
	int x[n],arr[n],brr[n];
	for(i=0;i<n;i++)
	scanf("%d",&x[i]);
	for(b=0;b<n;b++)
	{
		for(i=0;i<n;i++)
		arr[i]=1;
		i=0;
		while(1)
		{
			t=b+k*i;
			if(t>n-1)
			break;
			arr[t]=0;
			i++;
		}
		i=0;
		while(1)
		{
			t=b-k*i;
			if(t<0)
			break;
			arr[t]=0;
			i++;
		}
		e=0;
		s=0;
		for(i=0;i<n;i++)
		{
			if(arr[i]==0)
			continue;
			if(x[i]==1)
			e++;
			else if(x[i]==-1)
			s++;
		}
		if(e>s)
		brr[b]=e-s;
		else
		brr[b]=s-e;
	}
	t=0;
	for(i=0;i<n;i++)
	{
		if(t<brr[i])
		t=brr[i];
	}
	printf("%d\n",t);
	return 0;
}

#include<stdio.h>
//删掉最多的社交，或者删掉最多的测试
#define N 102
int main(){
    int n,k;
    scanf("%d%d",&n,&k);
    int i;
    int tab[N];
    char close[N];
    for(i=1;i<=n;i++){
        scanf("%d",&tab[i]);
    }
    int j;
    int answer=0;
    for(i=0;i<k;i++){
        for(j=1;j<=n;j++){
            close[j]=0;
        }
        for(j=1+i;j<=n;j+=k){
            close[j]=1;
        }
        int e=0;
        int s=0;
        for(j=1;j<=n;j++){
            if(!close[j]){
                if(tab[j]==1){
                    e++;
                }else{
                    s++;
                }
            }
        }
        if(e>s){
            if(answer<e-s){
                answer=e-s;
            }
        }else{
            if(answer<s-e){
                answer=s-e;
            }
        }
    }
    printf("%d\n",answer);
    return 0;
}

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
int main(){
	int n,k;
	while(scanf("%d%d",&n,&k)!=EOF){
		int arr[n],i,a[k],b[k],max=-1e9,suma=0,sumb=0;
		memset(a,0,sizeof(a));
		memset(b,0,sizeof(b));
		for(i=0;i<n;i++){
			scanf("%d",&arr[i]);
			if(arr[i]==1)
				suma++ ;
			else
				sumb++;
		}
		for(i=0;i<n;i++){
			if(arr[i]==1){
				a[i%k]++;
			}
			else{
				b[i%k]++;
			}
		}
		for(i=0;i<k;i++){
			if(abs(abs(suma-a[i])-abs(sumb-b[i]))>max)
				max=abs(abs(suma-a[i])-abs(sumb-b[i]));
		}
		printf("%d\n",max);
	}
}

#include<stdio.h>
int a[100];
int main(){
       int n,k,i,j,max=0;
       scanf("%d%d",&n,&k);
       for(i=0;i<n;i++)
              scanf("%d",&a[i]);
       for(i=0;i<k;i++){
              int c=0;
              for(j=0;j<n;j++){
                     if(j%k!=i)    c+=a[j];
              }
              if(c<0)       c=-c;
              if(max<c)     max=c;
       }
       printf("%d",max);
}

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>

#define SIZE 100
int main() {
	int n, a[100], k, i, j, e = 0, s = 0, et = 0, st = 0, max = 0;

	scanf ("%d %d", &n, &k);

	for (i = 0; i < n; i++) {
		scanf ("%d", &a[i]);
		if (a[i] == 1)
			e++;
		else
			s++;
	}

	for (i = 0; i < k; i++) {
		et = 0;
		st = 0;
		for (j = i; j < n; j += k)
			if (a[j] == 1)
				et++;
			else
				st++;

		if ((int) abs ((int) ((e - et) - (s - st))) > max)
			max = (int) abs ((int) ((e - et) - (s - st)));
	}

	printf ("%d", max);

	return 0;
}

#include <stdio.h>
void read(int *arr, int length) {
    for (int i=0; i<length; i++) scanf("%d",(arr+i));
}
int diff(int *arr, int length, int init, int b) {
    int test=0,social=0;
    for (int i=0; i<length; i++) {
        if (i%init!=b%init) {
            if (*(arr+i)==1) {
                test++;
            } else {
                social++;
            }
        }
    }
    return abs(test-social);
}
int maxim(int *arr, int length, int k) {
    int res=0,comp;
    for (int i=0; i<length; i++) {
        comp=diff(arr,length,k,i);
        if (res<comp) res=comp;
    }
    return res;
}
int main() {
    int len,tab;
    scanf("%d %d\n",&len,&tab);
    int browse[len];
    read(browse,len);
    printf("%d",maxim(browse,len,tab));
    return 0;
}

#include <stdio.h>
#include <string.h>

#define N 200

int a[N], t[N];

int abs(int n) {
    return n < 0 ? -n : n;
}

int max(int x, int y) {
    return x > y ? x : y;
}

int func(int b, int k, int n) {
    int i, cnt = 0;
    for (i = 1; i <= n; i++)
        t[i] = a[i];
    for (i = b; i <= n; i += k)
        t[i] = 0;
    for (i = b; i >= 1; i -= k)
        t[i] = 0;
    for (i = 1; i <= n; i++)
        cnt += t[i];
    return abs(cnt);
}

int main(int argc, char* argv[]) {
    int i, n, k, ans = 0, cnt;

    scanf("%d%d", &n, &k);
    for (i = 1; i <= n; i++)
        scanf("%d", &a[i]);

    for (i = 1; i <= n; i++) {
        cnt = func(i, k, n);
        ans = max(ans, cnt);
    }

    printf("%d\n", ans);

    return 0;
}

#include <stdio.h>
#include<math.h>
int main()
{
  int k,n;
  scanf("%d %d",&n,&k);
  int arr[n];
  for(int i=0;i<n;i++)
  scanf("%d",&arr[i]);
  int cnta=0,cntb=0;
  for(int i=0;i<n;i++)
  {
      if(arr[i]==1)
      cnta++;
      if(arr[i]==-1)
      cntb++;
  }
 // printf("%d %d\n",cnta,cntb);
  int max=0;
  int cntd=cnta,cnte=cntb;
  for(int i=0;i<n;i++)
  {
      cnta=cntd;
      cntb=cnte;
      for(int j=i;j>=0;j=j-k)
      {
          if(arr[j]==1)
      cnta--;
      if(arr[j]==-1)
      cntb--;
      }
      for(int j=i+k;j<n;j=j+k)
      {
          if(arr[j]==1)
      cnta--;
      if(arr[j]==-1)
      cntb--;
      //printf("inside: j:%d\n",j);
      }
     // printf("cnta:%d cntb:%d\n",cnta,cntb);
      if(abs(cnta-cntb)>max)
      {
      //printf("inside: %d\n",abs(cnta-cntb));
      max=abs(cnta-cntb);
      }
  }
  printf("%d",max);
  return 0;
}

#include<stdio.h>
int a[10000], ans[10000];
int main()
{
    int  n=0,k=0;
    scanf("%d %d",&n,&k);
    for(int i=0;i<n;++i)
    scanf("%d",&a[i]);
    int j=0;
while(j<k)
{
    for(int i=0;i<n;i++)
    {
         if(i%k!=j)
         {
             if(a[i]==1) ans[j]++;
             else ans[j]--;
         }
    }
    j++;
}
for(int i=0;i<k;++i)
if(ans[i]<0)ans[i]=-ans[i];
int max=-1;
for(int i=0;i<k;++i)
{
    if(ans[i]>max) max=ans[i];
}

printf("%d\n",max);
return 0;
}

#include<stdio.h>

int tab[110];
int abs(int a){
	int b;
	if(a>0){
		return a;
	}
	else return (-1)*a;
}
int main(){
	int n,k,presum=0,sum=0,des,max=0;
	scanf("%d %d",&n,&k);
	for(int i=0;i<n;i++){
		scanf("%d",tab+i);
	}
	for(int i=0;i<n;i++){
		presum+=tab[i];
	}
	for(int i=0;i<k;i++){
		for(int j=0;i+j*k<n;j++){
			sum+=tab[i+j*k];
		}
		des=presum-sum;
		if(max<abs(des))	max=abs(des);
		sum=0;
	}
	printf("%d",max);
}

#include <stdio.h>

int max(int a, int b){
    if(a > b)
        return a;
    return b;
}

int abs(int a){
    if(a < 0)
        return -a;
    return a;
}

int main(){
    int n, k;
    scanf("%d %d", &n, &k);
    int sum = 0, arr[k];
    for(int i = 0; i < k; i++){
        arr[i] = 0;
    }
    for(int i = 0; i < n; i++){
        int t;
        scanf("%d", &t);
        sum+=t;
        arr[i%k]+=t;
    }
    int mx = -(1<<30);
    int min = -mx;
    for(int i = 0; i < k; i++){
        if(arr[i] < min){
            min = arr[i];
        }
        if(arr[i] > mx){
            mx = arr[i];
        }
    }
    int ans = max(abs(sum-mx), abs(sum-min));
    printf("%d\n", ans);
}

#include<stdio.h>
#include<stdlib.h>

int main(){
    int n, k, sum1 = 0, sum2 = 0, res = 0;
    scanf("%d %d", &n, &k);
    int *a = (int *)calloc(k, sizeof(int));
    int *b = (int *)calloc(k, sizeof(int));
    for(int i = 0; i < n; ++i){
        int tmp;
        scanf("%d", &tmp);
        if(tmp == -1)
            ++a[i % k], ++sum1;
        else
            ++b[i % k], ++sum2;
    }
    for(int i = 0; i < k; ++i){
        int tmp = abs(sum1 - sum2 - a[i] + b[i]);
        res = tmp > res ? tmp : res;
    }
    printf("%d\n", res);
}

#include<stdio.h>
#include<math.h>
int main()
{
    int n,i,k,j,b=0,c=0,d=0,m=0;
    scanf("%d%d",&n,&k);
    int a[n];
    for(i=0;i<n;i++)
    {
        scanf("%d",&a[i]);
        if(a[i]==1)
            b++;
        else
            c++;

    }
    for(i=0;i<k;i++)
    {
        int s=b,f=c;
        for(j=i;j<n;j=j+k)
        {
            if(a[j]==1)
                s--;
            else
                f--;
        }
        d=abs(s-f);

        if(m<d)
            m=d;
    }
    printf("%d",m);
}

#include<stdio.h>
int main ()
{
	int n,k;
	scanf("%d %d",&n,&k);
	int arr[n+1];
	arr[0]=0;
	//int sum=0;
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&arr[i]);
		//sum=sum+arr[i];
	}
	int sand=0;
	int l=0;
	int max[k];
	for(int i=1;i<=k;i++)
	{
		sand=0;
		int ans[n+1];
		for(int j=0;j<=n;j++)
		{
			ans[j]=arr[j];
		}
		for(int j=i;j<=n;j+=k)
		{
			ans[j]=0;
		}
		for(int j=0;j<=n;j++)
		{
			sand=sand+ans[j];
		}
		if(sand<0)
		{
			max[l]=(-1)*sand;
			l++;
		}
		else
		{
			max[l]=sand;
			l++;
		}
	}
	int mad=0;
	for(int i=0;i<k;i++)
	{
		//printf("%d ",max[i]);
		if(max[i]>mad)
			mad=max[i];
	}
	printf("%d\n",mad);
}

#include<stdio.h>
#include<math.h>
int main(){
	int n,k,i,j;
	int a[100];
	int e=0,s=0,de,ds;
	int max=0,diff;
	scanf("%d %d",&n,&k);
	for(i=0;i<n;i++)scanf("%d",&a[i]);
	for(i=0;i<n;i++)if(a[i]==1)e++;else s++;
	for(i=0;i<k;i++){
		de=0;
		ds=0;
		for(j=i;j<n;j+=k)if(a[j]==1)de++;else ds++;
		diff=abs(e-de-s+ds);
		if(diff>max)max=diff;
	}
	printf("%d",max);
}

#include<stdio.h>
#include<math.h>

int main()
{
    int n, k, i, j, c, es = 0, ss = 0, e = 0, s = 0, max = -1, a[105];
    scanf("%d %d", &n, &k);
    for(i = 1; i <= n; i++)
    {
        scanf("%d", &a[i]);
        if(a[i] == 1)
            es++;
        else
            ss++;
    }
    for(i = 1; i <= k; i++)
    {
        e = es;
        s = ss;
        for(j = 0; (i + j) <= n; j += k)
        {
            c = i + j;
            if(a[c] == 1)
                e--;
            else
                s--;
        }
        if(abs(e - s) > max)
            max = abs(e - s);
    }
    printf("%d\n", max);
    return 0;
}

#include <Stdio.h>
#include <String.h>
#include <math.h>

int main() {
	int n, k;
	while (scanf("%d%d", &n, &k) != EOF) {
		int arr[n];
		int cnt_fu = 0;
		int cnt_zheng = 0;
		int result = -1;
		memset(arr, 100, sizeof(arr));

		for (int i = 0 ; i < n; i++) {
			scanf("%d", &arr[i]);
			if (arr[i] == -1) {
				cnt_fu++;
			}
			if (arr[i] == 1) {
				cnt_zheng++;
			}
		}
		int b = 0;
		int i = 0;
		int c = 0;
		for (b = 0; b < n; b++) { // b <= n
			int tmp[n];
			memcpy(tmp, arr, sizeof(arr));
			int cnt_fu_jian = 0;
			int cnt_zheng_jian = 0;
			for (i = -1 * n ; i <= n; i++) {
				c = b + i * k;
				if (c < 0 || c > n) {
					continue;
				}
				else if (arr[c] == -1) {
					cnt_fu_jian++;
					tmp[c] = 0;
				}
				else if (arr[c] == 1) {
					cnt_zheng_jian++;
					tmp[c] = 0;
				}
			}
			int cnt_fu_sum = cnt_fu - cnt_fu_jian;
			int cnt_zheng_sum = cnt_zheng - cnt_zheng_jian;
			int new = (int)abs(cnt_fu_sum - cnt_zheng_sum);
			// printf("new:%d\tb:%d\ti:%d\tc:%d\n", new, b, i, c);
			if (new > result) {
				result = new;
			}
		}
		printf("%d\n", result);
	}
	return 0;
}

#include<stdio.h>
#include<math.h>
int main()
{
    int n,k,a[100],i,j,c=0,d=0,mx=0;
    scanf("%d%d",&n,&k);
    for(i=0;i<n;i++)
        scanf("%d",&a[i]);
    for(j=0;j<k;j++)
    {
        for(i=0;i<n;i++)
        {
            if((i+1)%k==j)
                continue;
            if(a[i]==1)
                c++;
            else
                d++;
        }
        if(abs(c-d)>mx)
            mx=abs(c-d);
        c=0;
        d=0;
    }
    printf("%d\n",mx);
    return 0;
}

#include <stdio.h>
#include <math.h>
int n,k;
int dem[101];
int main()
{
	int web,i;
	scanf("%d %d",&n,&k);
	for(i=1 ; i<=n ; i++)
	{
		scanf("%d",&web);
		dem[i%k]+=web;
		dem[k]+=web;
	}

	int kq=0;
	for(i=0 ; i<k ; i++)
	{
		dem[i]=abs(dem[k]-dem[i]);
		kq=kq>dem[i]?kq:dem[i];
	}

	printf("%d",kq);
	return 0;
}

#include<stdio.h>
#include<stdlib.h>
int main()
{
    int n,k,b,c,e,s,j,val,max,i;
    scanf("%d%d",&n,&k);
    int *a=(int*)calloc(n,sizeof(int));
    for(i=0;i<n;i++)
        scanf("%d",a+i);

    max=0;
    for(b=0;b<k;b++)
    {
        e=0,s=0;

        for(j=0;j<n;j++)
        {
            if((j-b)%k!=0)
            {
                if(a[j]==1) e++;
                else s++;
            }
        }
        val=abs(e-s);
          //printf("val=%d\n",val);
        if(val>max)
          max=val;
    }
    printf("%d",max);
}

#include<stdio.h>

  int main(){
    int n,k;
    scanf("%d%d",&n,&k);
    int ar[n];
    for(int i=0;i<n;i++)
      scanf("%d",ar+i);
    int max=0;
    for(int i=1,a=0,j;i<=n;i++){
      a=0;
      for(j=0;j<n;j++){
        if((j+1-i)%k==0)
          continue;
        if(ar[j]==1)a++;
        else a--;
      }
      if(a<0)a=-a;
      max=max>=a?max:a;
    }
    printf("%d\n",max);
    return 0;
  }

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
    int n,k,i,b,s;
    scanf("%d%d",&n,&k);
    int tab[n],store[n],sum[k];
    for (i=0;i<n;i++)
    {
        scanf("%d",&tab[i]);
        store[i]=tab[i];
    }
    for (b=0;b<k;b++)
    {
        for (i=b;i<n;i+=k)
        {
            tab[i]=0;
        }
        for (i=0;i<n;i++)
        {
            if (tab[i]==1) s++;
            else if (tab[i]==-1) s--;
        }
        sum[b]=abs(s);
        s=0;
        for (i=b;i<n;i+=k)
        {
            tab[i]=store[i];
        }
    }
    for (i=1;i<k;i++)
    {
        if (sum[0]<sum[i])
            sum[0]=sum[i];
    }
    printf("%d",sum[0]);
    return 0;
}

#include <stdio.h>
#include<stdlib.h>
#include<math.h>

int main() {
	int n, k, i, j, e=0, s=0, max, e_cpy, s_cpy;
	int* ptr;
	scanf("%d %d", &n, &k);
	ptr=(int*)malloc(n*sizeof(int));
	for(i=0;i<n;i++){
        scanf("%d", &ptr[i]);
        if(ptr[i]==1) e++;
        else s++;
	}
	max=0;
	for(i=0;i<k;i++){
        e_cpy=e; s_cpy=s;
        for(j=0;i+j*k<n;j++){
            if(ptr[i+j*k]==1)e_cpy--;
            else s_cpy--;
        }
        if(abs(e_cpy-s_cpy)>max) max=abs(e_cpy-s_cpy);
	}
    printf("%d", max);

	return 0;
}

#include<stdio.h>
#include<stdlib.h>
int max(int a,int b)
{
    return a>b?a:b;
}
int main()
{
    int n,k,i,j,plus,neg,one=0,two=0,total,count,final=0;
    scanf("%d %d",&n,&k);
    int a[n];
    for(i=0;i<n;i++)
    {
    scanf("%d",a+i);
    if(a[i]==1)
    one++;
    else
    two++;
    }
    for(i=0;i<n;i++)
    {
        j=0;
        count=i;
        plus=0;
        neg=0;
        total=count-j*k;
        while(total>=0)
        {
            j++;
            if(a[total]==1)
            plus++;
            else
            neg++;
            total=count-j*k;
        }
        j=1;
        total=count+j*k;
        while(total<n)
        {
            j++;
            if(a[total]==1)
            plus++;
            else
            neg++;
            total=count+j*k;
        }
        final=max(final,abs((one-plus)-(two-neg)));
    }
    printf("%d",final);
    return 0;
}

#include<stdio.h>
#include<string.h>
int absolute(int a, int b){
	return a > b ? a-b : b-a;
}

int main(){
	int n,k,i,j;
	scanf("%d%d",&n,&k);
	int a[n];
	int te = 0,ts = 0;

	int b[k][2];
	for(i = 0;i < k;i++){
		b[i][0] = 0;
		b[i][1] = 0;
	}

	for(i = 0;i < n;i++){
		scanf("%d",&a[i]);
		if(a[i] == 1){
			te++;
			b[i%k][0]++;
		}
		else{
			ts++;
			b[i%k][1]++;
		}
	}

	int max = 0;
	for(i = 0;i < k;i++){
		int temp = absolute(te - b[i][0],ts - b[i][1]);
		if(temp > max){
			max = temp;
		}
	}
	printf("%d\n",max);
	return 0;
}

#include<stdio.h>
#include<stdlib.h>
int main()
{
    int i,n,k,e=0,s=0,a,b,j,max=0;
    scanf("%d %d",&n,&k);
    int arr[n];
    for(i=0;i<n;i++)
    {
        scanf("%d",&arr[i]);
        if(arr[i]==1)e++;
        else s++;
    }
    for(i=0;i<k;i++)
    {
        a=e;
        b=s;
        for(j=i;j<n;j+=k)
        {
            if(arr[j]==1)a--;
            else b--;
        }
        if(abs(a-b)>max)max=abs(a-b);
    }
    printf("%d",max);
}

#include <stdio.h>
#include <math.h>
#include <stdlib.h>

int main()
{
        int n,k;
        scanf("%d %d",&n,&k);

        int a[n+1];
        for(int i=1;i<n+1;i++)
            scanf("%d",&a[i]);

        int a1=0,a2=0;
        for(int i=1;i<n+1;i++)
        {
            if(a[i]==1)
            {
                a1++;
            }
            else
            {
                a2++;
            }
        }
        int max=0;
        for(int i=1;i<n+1;i++)
        {

            int e=a1,s=a2;
            int index=i;
            for(int j=i;j<n+1;j=j+k)
            {
                if(a[j]==1)
                {
                    e--;
                }
                else
                {
                    s--;
                }
            }
            for(int j=i-k;j>0;j=j-k)
            {
                if(a[j]==1)
                {
                    e--;
                }
                else
                {
                    s--;
                }
            }

            if(abs(e-s)>max)
                max=abs(e-s);
        }
        printf("%d",max);
}

#include<stdio.h>
#include<math.h>
int main(void)
{
	int n, k;
	scanf("%d%d",&n,&k);
	int arr[110];
	int ctre=0;
	int ctrs=0;
	for(int q=0;q<n;q++)
	{
		scanf("%d",&arr[q]);
		if(arr[q]==-1)
			ctrs++;
		else ctre++;

	}
	int ans=0;
//printf("ctre:%d	ctrs:%d\n",ctre,ctrs);

	for(int w=0;w<n;w++)
	{
		int ce=ctre;
		int cs=ctrs;
		int ptr=w;
		while(ptr<n)
		{
			if(arr[ptr]==1)
				ce--;
			if(arr[ptr]==-1)
				cs--;
//printf("ptr:%d\n",ptr);
	ptr+=k;
//printf("ctre:%d		ctrs:%d\n",ce,cs);

		}
		ptr=w-k;
		while(ptr>=0)
		{
                       if(ptr>=0)
{
			if(arr[ptr]==1)
				ce--;
			if(arr[ptr]==-1)
				cs--;
			ptr-=k;
}
//printf("here\n");
//printf("ptr:%d\n",ptr);            //     ptr+=k;
//printf("ctre:%d         ctrs:%d\n",ce,cs);

		}
//		printf("w:%d\n",w);
//		printf("fabs(cs-ce):%lf\n",fabs(cs-ce));

		if(fabs(cs-ce)>ans)
			ans=fabs(cs-ce);

	}
	printf("%d",ans);
}

#include<stdio.h>
#include<math.h>

int main(){
    int n,k,e=0,s=0,max=0,temp=0;
    scanf("%d %d",&n,&k);
    int str[n];
    for(int i=0;i<n;i++){
        scanf("%d",&str[i]);
    }
    for(int b=0;b<k;b++){
        int j=0;
        s=0;
        e=0;
        for(int i=0;i<n;i++){
            if(i==b+j*k) j++;
            else{
                if(str[i]==1) e++;
                if(str[i]==-1) s++;
            }
        }
        temp=abs(e-s);
        if(temp>max) max=temp;
    }
    printf("%d",max);
    return 0;
}

#include<stdio.h>
int main()
{
    int n,k;
    while(scanf("%d %d",&n,&k)!=EOF)
    {
        getchar();
        int a[2000]={0},x=0,y=0;
        for(int i=1;i<=n;i++)
        {
            scanf("%d",&a[i]);
            if(a[i]==1) x++;
            else y++;
        }
        getchar();
        int max=0;
        for(int i=1;i<=k;i++)
        {
            int x1=x,y1=y;
            for(int j=i;j<=n;j+=k)
            {
                if(a[j]==1) x1--;
                else y1--;
            }
            int m;m=x1-y1;
            if(m<0) m=-m;
            if(m>max) max=m;
        }
        printf("%d\n",max);
    }
    return 0;
}

#include <stdio.h>
#include <string.h>

#define MAXLEN 100

int main()
{
	int n,k, tabs[MAXLEN+1];
	int l,b,sum,tmp[MAXLEN+1];
	int ans;

	while(scanf("%d%d",&n,&k)==2)
	{
		ans=0;
		for(l=1;l<=n;l++) scanf("%d",&tabs[l]);

		for(b=1;b<=n;b++)
		{
			memcpy((void *)tmp,(void *)tabs,sizeof(int)*(n+1));

			for(l=b;l<=n;l+=k) tmp[l]=0;
			for(l=b-k;l>0;l-=k) tmp[l]=0;

			for(l=1,sum=0;l<=n;l++) sum+=tmp[l];
			sum=(sum<0)?-sum:sum;

			if(sum>ans) ans=sum;
		}

		printf("%d\n", ans);
	}

	return 0;
}

#include<stdio.h>

int main()
{
    int n,k,max=0,dif=0;
    scanf("%d%d",&n,&k);
    int ar[n],br[n];
    for(int i=0;i<n;i++)
    scanf("%d",&br[i]);
    for(int b=0;b<n;b++)
    {
    for(int x=0;x<n;x++)
    ar[x]=br[x];
    int i=0,t=0,s=0;
    while(b-(i*k)>=0||b+(i*k)<n)
    {
    if(b-(i*k)>=0)
    ar[b-(i*k)]=0;
    if(b+(i*k)<n)
    ar[b+(i*k)]=0;
    i++;
    }
    for(int j=0;j<n;j++)
    {
    //printf("%d ",ar[j]);
    if(ar[j]==-1)
    s++;
    else if(ar[j]==1)
    t++;
    }
    if(t>s)
    dif=t-s;
    else
    dif=s-t;
    if(dif>max)
    max=dif;
    }
    printf("%d",max);
    return 0;
}

#include<stdio.h>
#include<math.h>
int main()
{
	int n,q=0,w=0,c;
	int k;
	int a[10000];
	int b[10000],max=-999999;
	scanf("%d %d",&n,&k);
	if(n==1)
	{
		scanf("%d",&c);

		printf("1\n");
		return 0;
	}
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&a[i]);
	}
	for(int b=1;b<=n;b++)
	{	q=0;w=0;
		for(int j=1;j<=n;j++)
		{
			if((j-b)%k==0)

			{continue;

			}
			if(a[j]==1)
			w++;
			else
			q++;
		}
		if(abs(q-w)>max)
		max=abs(q-w);
		printf("%d %d\n",q,w);

	}

	printf("%d",max);

	return 0;
}

#include<stdio.h>
#include<math.h>
int main()
{
	int n,q=0,w=0,c;
	int k;
	int a[10000];
	int b[10000],max=-999999;
	scanf("%d %d",&n,&k);
	if(n==1)
	{
		scanf("%d",&c);

		printf("1\n");
		return 0;
	}
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&a[i]);
	}
	for(int b=1;b<=n/2;b++)
	{	q=0;w=0;
		for(int j=1;j<=n;j++)
		{
			if((j-b)%k==0)

			{continue;

			}
			if(a[j]==1)
			w++;
			else
			q--;
		}
		if(q-w>max)
		max=abs(q-w);

	}

	printf("%d",max);

	return 0;
}

#include <stdio.h>
#include <math.h>
#include <stdlib.h>

int main()
{
        int n,k;
        scanf("%d %d",&n,&k);

        int a[n+1];
        for(int i=1;i<n+1;i++)
            scanf("%d",&a[i]);

        int max=0;
        for(int i=1;i<n+1;i++)
        {
            int c;
            if(i/k==0)
            {
                c=i;
            }
            else
            {
                if(i%k==0)
                c=1;
                else if((i+1)%k==0)
                c=2;
                else
                c=3;
            }
            int j=0,e=0,s=0;
            for(int d=1;d<n+1;d++)
            {
                if(d==(c+j*k))
                {
                    j++;
                }
                else
                {
                    if(a[d]==1)
                        e++;
                    else
                        s++;
                }
            }

            if(abs(e-s)>max)
                max=abs(e-s);
        }
        printf("%d",max);
}

#include <stdio.h>
#include <math.h>
#include <stdlib.h>

int main()
{
        int n,k;
        scanf("%d %d",&n,&k);

        int a[n+1];
        for(int i=1;i<n+1;i++)
            scanf("%d",&a[i]);

        int max=0;
        for(int i=1;i<n+1;i++)
        {
            int j=-(i/k),e=0,s=0;
            for(int d=1;d<n+1;d++)
            {
                if(d==(i+j*k))
                {
                    j++;
                }
                else
                {
                    if(a[d]==1)
                        e++;
                    else
                        s++;
                }
            }

            if(abs(e-s)>max)
                max=abs(e-s);
        }
        printf("%d",max);
}

#include <stdio.h>
#include <math.h>
int main()
{
    int n,k;
    scanf("%d %d",&n,&k);
    int arr[n];
    for(int i = 0;i<n; i++)
        scanf("%d",&arr[i]);
    //int e,s;
    int ans=0;
    for(int i = 0; i < n/2; i++)
    {
        int e=0,s=0;
        int temp[n];
        for(int j=0;j<n;j++)
            temp[j]=arr[j];
        for(int j = i; j < n;)
        {
            temp[j]=0;
            j+=k;
        }
        for(int j = 0; j < n; j++)
        {
            if(temp[j]==1)
                e++;
            else if(temp[j]==-1)
                s++;
        }
        if(fabs(e-s)>=ans)
            ans=fabs(e-s);
    }
    printf("%d",ans);
    return 0;
}

#include<stdio.h>
int main(){
   int n , k , j , e = 0 , s=0  , num = 0 , min = 0 , max = 0 ;
   scanf("%d %d",&n , &k) ;
   int i , a[n]  , sum = 0 ;
   for(i=0 ; i<n ; i++){
       scanf("%d", &a[i])   ;
       sum += a[i]  ;
   }
if(sum>=0){
    //int num = 0 , int min = 0 ;
for(j=0 ; j<n ; j++){}
  for(i=j ; i<n ; i = i+k ){
        num += a[i]   ;
  }
if(min>num){
    min = num ;
    int index = j ;
   }

for(i=0 ; i<n ; i++ ){
    if((i==j)||((i-j)%k==0)) continue ;
    else{
    if(a[i]==1) e++ ;
    else s++ ;
  }
 }
 printf("%d",e-s)  ;
}else{
    //int num = 0 , int max = 0 ;
for(j=0 ; j<n ; j++){}
  for(i=j ; i<n ; i = i+k ){
        num += a[i]   ;
  }
if(max<num){
    max = num ;
    int index = j ;
   }
for(i=0 ; i<n ; i++ ){
    if((i==j)||((i-j)%k==0)) continue ;
    else{
    if(a[i]==1) e++ ;
    else s++ ;
  }
 }
 printf("%d", e-s)   ;
}
    return 0 ;
}

#include<stdio.h>
#include<stdlib.h>
#include<stdint.h>
#include<inttypes.h>

typedef int64_t i64;
typedef int32_t i32;

static void print_int(i64 n){if(n<0){putchar('-');n=-n;}if(n==0){putchar('0');return;}int s[20],len=0;while(n>0){s[len++]=n%10+'0';n/=10;}while(len>0){putchar(s[--len]);}}
static i64 read_int(void){int prev='\0';int c=getchar();while(!('0'<=c && c<='9')){prev=c;c=getchar();}i64 res=0;while('0'<=c && c<='9'){res=10*res+c-'0';c=getchar();}return prev=='-'?-res:res;}

#define MAX(a,b) ((a)>(b)?(a):(b))
#define ABS(a) ((a)>(0)?(a):-(a))

void run (void) {
  i32 n = read_int();
  i32 k = read_int();
  i32 *cnt = (i32 *) calloc (k, sizeof (i32));
  i32 sum = 0;
  for (i32 i = 0; i < n; ++i) {
    i32 a = read_int();
    cnt[a % k]++;
    sum += a;
  }
  i32 max = 0;
  for (i32 i = 0; i < k; ++i) {
    max = MAX(max, ABS(sum - cnt[i]));
  }
  print_int (max);
  puts("");
}

int main (void) {
  run ();
  return 0;
}

#include<stdio.h>
#include<stdlib.h>
#include<stdint.h>
#include<inttypes.h>

typedef int64_t i64;
typedef int32_t i32;

static void print_int(i64 n){if(n<0){putchar('-');n=-n;}if(n==0){putchar('0');return;}int s[20],len=0;while(n>0){s[len++]=n%10+'0';n/=10;}while(len>0){putchar(s[--len]);}}
static i64 read_int(void){int prev='\0';int c=getchar();while(!('0'<=c && c<='9')){prev=c;c=getchar();}i64 res=0;while('0'<=c && c<='9'){res=10*res+c-'0';c=getchar();}return prev=='-'?-res:res;}

#define MAX(a,b) ((a)>(b)?(a):(b))
#define ABS(a) ((a)>(0)?(a):-(a))

void run (void) {
  i32 n = read_int();
  i32 k = read_int();
  i32 *cnt = (i32 *) calloc (k, sizeof (i32));
  i32 sum = 0;
  for (i32 i = 0; i < n; ++i) {
    i32 a = read_int();
    cnt[i % k]++;
    sum += a;
  }
  i32 max = 0;
  for (i32 i = 0; i < k; ++i) {
    max = MAX(max, ABS(sum - cnt[i]));
  }
  print_int (max);
  puts("");
}

int main (void) {
  run ();
  return 0;
}

#include <stdio.h>
#include <math.h>
int main()
{
    static int a[101], t, n, k, sum, max ,i;
    scanf("%d%d", &n, &k);
    for(i=0; i<n; i++)
    {
        scanf("%d",&t);
        a[t%k] += t;
        sum += t;
    }
    for(i=0; i<k; i++)
    {
        if(max < abs(sum-a[i]))
            max = abs(sum-a[i]);
    }
    printf("%d\n", max);
    return 0;
}

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
int main(){
	int n,k;
	while(scanf("%d%d",&n,&k)!=EOF){
		int arr[n],i,a[k],b[k],max=-1e9,suma=0,sumb=0;
		memset(a,0,sizeof(a));
		memset(b,0,sizeof(b));
		for(i=0;i<n;i++){
			scanf("%d",&arr[i]);
			if(arr[i]==1)
				suma++ ;
			else
				sumb++;
		}
		for(i=0;i<n;i++){
			if(arr[i]==1){
				a[i%k]++;
			}
			else{
				b[i%k]++;
			}
		}
		for(i=0;i<k;i++){
			if(abs(a[i]-b[i])>max)
				max=abs(abs(suma-a[i])-abs(sumb-b[i]));
		}
		printf("%d\n",max);
	}
}

#include<stdio.h>
#include<math.h>
int main()
{
    int n,k,a[100],i,j,c=0,d=0,mx=0;
    scanf("%d%d",&n,&k);
    for(i=0;i<n;i++)
        scanf("%d",&a[i]);
    for(j=1;j<=k;j++)
    {
        for(i=0;i<n;i++)
        {
            if((i+1)%k==j)
                continue;
            if(a[i]==1)
                c++;
            else
                d++;
        }
        if(abs(c-d)>mx)
            mx=abs(c-d);
        c=0;
        d=0;
    }
    printf("%d\n",mx);
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
    int n,k,i,b=0;
    scanf("%d%d",&n,&k);
    int tab[n],store[n],sum[k];
    for (i=0;i<n;i++)
    {
        scanf("%d",&tab[i]);
        store[i]=tab[i];
        if (i<k)
            sum[i]=0;
    }

    for (b=0;b<k;b++)
    {
        for (i=0;i<n;i++)
            tab[i]=store[i];
        for (i=b;i<n;i+=k)
        {
            tab[b]=0;
        }
        for (i=0;i<n;i++)
        {
            if (tab[i]==1) sum[b]++;
            else if (tab[i]==-1) sum[b]--;
        }
        sum[b]=abs(sum[b]);
    }
    for (i=0;i<k;i++)   printf("%d\t",sum[i]);
    for (i=1;i<k;i++)
    {
        if (sum[0]<sum[i])
            sum[0]=sum[i];
    }
    printf("%d",sum[0]);
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
    int n,k,i,b,s;
    scanf("%d%d",&n,&k);
    int tab[n],store[n],sum[k];
    for (i=0;i<n;i++)
    {
        scanf("%d",&tab[i]);
        store[i]=tab[i];
    }
    for (b=0;b<k;b++)
    {
        for (i=b;i<n;i+=k)
        {
            tab[i]=0;
        }
        for (i=0;i<n;i++)
        {
            if (tab[i]==1) s++;
            else if (tab[i]==-1) s--;
        }
        sum[b]=abs(s);
        s=0;
        for (i=b;i<n;i+=k)
        {
            tab[b]=store[b];
        }
    }
    for (i=1;i<k;i++)
    {
        if (sum[0]<sum[i])
            sum[0]=sum[i];
    }
    printf("%d",sum[0]);
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
    int n,k,i,b=0;
    scanf("%d%d",&n,&k);
    int tab[n],store[n],sum[k];
    for (i=0;i<n;i++)
    {
        scanf("%d",&tab[i]);
        store[i]=tab[i];
        if (i<k)
            sum[i]=0;
    }

    for (b=0;b<k;b++)
    {
        for (i=0;i<n;i++)
            tab[i]=store[i];
        for (i=b;i<n;i+=k)
        {
            tab[b]=0;
        }
        for (i=0;i<n;i++)
        {
            if (tab[i]==1) sum[b]++;
            else if (tab[i]==-1) sum[b]--;
        }
        sum[b]=abs(sum[b]);
    }
    for (i=1;i<k;i++)
    {
        if (sum[0]<sum[i])
            sum[0]=sum[i];
    }
    printf("%d",sum[0]);
    return 0;
}

#include<stdio.h>
#include<math.h>

int main(){
    int n,k,e=0,s=0,max=0,temp=0;
    scanf("%d %d",&n,&k);
    int str[n];
    for(int i=0;i<n;i++){
        scanf("%d",&str[i]);
    }
    for(int b=0;b<k-1;b++){
        int j=0;
        for(int i=0;i<n;i++){
            if(i==b+j*k) j++;
            else{
                if(str[i]==1) e++;
                if(str[i]==-1) s++;
            }
        }
        temp=abs(e-s);
        if(temp>max) max=temp;
    }
    printf("%d",max);
    return 0;
}

#include<stdio.h>
#include<math.h>

int main(){
    int n,k,e=0,s=0,max=0,temp=0;
    scanf("%d %d",&n,&k);
    int str[n];
    for(int i=0;i<n;i++){
        scanf("%d",&str[i]);
    }
    for(int b=0;b<k-1;b++){
        int j=0;
        s=0;
        e=0;
        for(int i=0;i<n;i++){
            if(i==b+j*k) j++;
            else{
                if(str[i]==1) e++;
                if(str[i]==-1) s++;
            }
        }
        temp=abs(e-s);
        if(temp>max) max=temp;
    }
    printf("%d",max);
    return 0;
}

#include<stdio.h>
#include<math.h>
#include<string.h>
#define Max 100000
int main(){
	int n,k;
	int c,b,i;
	int num[Max];
	int num1[Max];
	int sum1=0,sum2=0,r[Max];
	int j,e,f,a=0;
	int temp=0;
	scanf("%d%d",&n,&k);
	for(j=0;j<n;j++){
		scanf("%d",&num[j]);
	}
	int q=k;
	while(b=--q){
		i=0;
		sum1=0;
		sum2=0;
		c=0;
		for(j=0;j<n;j++){
			num1[j]=num[j];
		}
		while(c<=n){
			c=b+i*k;
			num1[c-1]=0;
			i++;
		}
//		for(j=0;j<n;j++){
//			printf("%d",num1[j]);
//			}
		for(j=0;j<n;j++){
			if(num1[j]==1){
				sum1++;
			}
			if(num1[j]==-1){
				sum2++;
			}
//			printf(" %d%d ",sum1,sum2);
		}
		int l;
		l=sum1-sum2;
		r[a]=abs(l);
//		printf("    %d       ",r[a]);
		a++;
	}
	for(e=0;e<a-1;e++)
		for(f=e+1;f<a;f++)
			if(r[e]<r[f])
			{
				temp=r[e];
				r[e]=r[f];
				r[f]=temp;
			}
	printf("%d",r[0]);
	return 0;
}

#include<stdio.h>
#include<math.h>
#include<string.h>
#define Max 100
int main(){
	int n,k;
	int c,b,i;
	int num[Max];
	int num1[Max];
	int sum1=0,sum2=0,r[Max];
	int j,e,f,a=0;
	int temp=0;
	scanf("%d%d",&n,&k);
	for(j=0;j<n;j++){
		scanf("%d",&num[j]);
	}
	int q=k;
	while(b=--q){
		i=0;
		sum1=0;
		sum2=0;
		c=0;
		for(j=0;j<n;j++){
			num1[j]=num[j];
		}
		while(c<=n){
			c=b+i*k;
			num1[c-1]=0;
			i++;
		}
//		for(j=0;j<n;j++){
//			printf("%d",num1[j]);
//			}
		for(j=0;j<n;j++){
			if(num1[j]==1){
				sum1+=num1[j];
			}
			if(num1[j]==-1){
				sum2+=num1[j];
			}
//			printf(" %d%d ",sum1,sum2);
		}
		int l;
		l=sum1-sum2;
		r[a]=abs(l);
//		printf("    %d       ",r[a]);
		a++;
	}
	for(e=0;e<a-1;e++)
		for(f=e+1;f<a;f++)
			if(r[e]<r[f])
			{
				temp=r[e];
				r[e]=r[f];
				r[f]=temp;
			}
	printf("%d",r[0]);
	return 0;
}

#include<stdio.h>
#include<math.h>
#include<string.h>
#define Max 100000
int main(){
	int n,k;
	int c,b,i;
	int num[Max];
	int num1[Max];
	int sum1=0,sum2=0,r[Max];
	int j,e,f,a=0;
	int temp=0;
	scanf("%d%d",&n,&k);
	for(j=0;j<n;j++){
		scanf("%d",&num[j]);
	}
	int q=k;
	while(b=--q){
		i=0;
		sum1=0;
		sum2=0;
		c=0;
		for(j=0;j<n;j++){
			num1[j]=num[j];
		}
		while(c<=n){
			c=b+i*k;
			num1[c-1]=0;
			i++;
		}
//		for(j=0;j<n;j++){
//			printf("%d",num1[j]);
//			}
		for(j=0;j<n;j++){
			if(num1[j]==1){
				sum1+=num1[j];
			}
			if(num1[j]==-1){
				sum2+=num1[j];
			}
//			printf(" %d%d ",sum1,sum2);
		}
		int l;
		l=sum1-sum2;
		r[a]=abs(l);
//		printf("    %d       ",r[a]);
		a++;
	}
	for(e=0;e<a-1;e++)
		for(f=e+1;f<a;f++)
			if(r[e]<r[f])
			{
				temp=r[e];
				r[e]=r[f];
				r[f]=temp;
			}
	printf("%d",r[0]);
	return 0;
}

#include<stdio.h>

int main() {
    int n, k;
    int arr[105];

    scanf("%d %d", &n, &k);
    int cons = 0;
    for(int i =0; i< n; i++) {
        scanf("%d", &arr[i]);
        cons += arr[i];
    }

    int result = 0;

    for(int b= 0; b < n; b++) {
        int temp= cons;
        for(int i = 0; i*k < n; i++) {
            if(b - i*k > 0) temp -= arr[b - i * k];
            if(b + i*k < n && i != 0) temp -= arr[b + i * k];
        }
        if( temp < 0 ) temp = -1 * temp;
        if( temp > result) result = temp;
    }

    printf("%d", result);

    return 0;
}

#include<stdio.h>
#include<math.h>
int main()
{
	int n,q=0,w=0,c;
	int k;
	int a[10000];
	int b[10000],max=-999999;
	scanf("%d %d",&n,&k);
	if(n==1)
	{
		scanf("%d",&c);

		printf("1\n");
		return 0;
	}
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&a[i]);
	}
	for(int b=1;b<=n;b++)
	{	q=0;w=0;
		for(int j=1;j<=n;j++)
		{
			if((j-b)%k==0)

			{continue;

			}
			if(a[j]==1)
			w++;
			else
			q--;
		}
		if(q-w>max)
		max=abs(q-w);

	}

	printf("%d",max);

	return 0;
}


#include <stdio.h>
int main()
{
    long long int n,k,a,b,c;
    scanf("%I64d %I64d",&n, &k);
    if(n%2!=0)
    {
        a=n/2+1;
    }
    else
    {
        a=n/2;
    }
    if(k<=a)
    {
        b=2*k-1;
    }
    else if(k>a)
    {
        b=2*(k-a);
    }
    printf("%I64d",b);
    return 0;
}

#include<stdio.h>
int main()
{
    long long n,k,s,r;

    scanf("%lld %lld",&n,&k);
    if(n%2==0)
        s=n/2;
    else
        s=(n/2)+1;
    if(k<=s)
        printf("%lld",((2*k)-1));
    else
          printf("%lld",((k-s)*2));
    return 0;
}

#include <stdio.h>
long long int a,b;

int main(){
    scanf("%lld %lld",&a,&b);
    if (a%2==0)
    {
        if (2*b-1<a)
        {
            printf("%lld",2*b-1);
        }
        else
        {
            printf("%lld",(b-a/2)*2);
        }
    }
    else
    {
        if (2*b-1<=a)
        {
            printf("%lld",2*b-1);
        }
        else
        {
            printf("%lld",((b-a/2)-1)*2);
        }
    }
    return 0;
}

#include <stdio.h>
long long int i,j,k,m,n,a,b;
int main()
{
    scanf("%lld %lld",&a,&b);
    if(a%2==0)
    {
    if(2*b-1<a)
    {
        printf("%lld",2*b-1);
        }
        else
        {
            printf("%lld",(b-a/2)*2);

        }
    }
        else
        {
        if(2*b-1<=a)
        {
            printf("%lld",2*b-1);
        }
        else
        {
        printf("%lld",((b-a/2)-1)*2);
        }

    }

        return 0;
    }

#include <stdio.h>

int main()
{
	long long n, k;
	scanf("%I64d%I64d", &n, &k);
	long long even;
	if(n%2==0)
		even=n/2;
	else
		even=(n/2)+1;
	if(k<=even)
		printf("%I64d\n", 2*k-1);
	else
		printf("%I64d\n", 2*(k-even));
	return 0;
}

#include<stdio.h>
int main()
{
long long n,k,c=0,i=1,j=2,d;
scanf("%I64d %I64d",&n,&k);
if(n%2==0)
d=n/2;
else
d=n/2+1;
if(k>d)
{
k=k-d;
printf("%I64d",k*2);
}
else
printf("%I64d",k*2-1);
return 0;
}

#include<stdio.h>

int main()
{
    long long n, k;
    scanf("%lld%lld",&n,&k);
    if(n%2==0)
    {
    if(k<=n/2)
    printf("%lld",(k*2)-1);
    else
    printf("%lld",(k-(n/2))*2);
    }
    else
    {
    if(k<=(n/2)+1)
    printf("%lld",(k*2)-1);
    else
    printf("%lld",(k-((n/2)+1))*2);
    }
    return 0;
}

#include<stdio.h>
int main()
{
    long long int n,k,m;

    scanf("%lld %lld",&n,&k);

    if(n%2==0)
    {
        m=n/2;
    }
    else if(n%2!=0)
    {
        m=(n+1)/2;
    }

    if(k<=m)
    {
        printf("%lld",(k*2)-1);
    }
    else
    {
        printf("%lld",(k-m)*2);
    }
}

#include <stdio.h>

int main(void)
{
    long long int n =0, k=0;
    scanf("%lld %lld",&n, &k);
    if (n%2 == 0)
    {
        if (k <= n/2)
        {
            printf("%lld", k*2-1);
        }
        else if (k > n/2)
        {
            k= k-(n/2);
            printf("%lld", k*2);
        }
    }
    else
    {
        if (k <= n/2+1)
        {
            printf("%lld", k*2-1);
        }
        else if (k > n/2 +1)
        {
            k= k- n/2 -1;
            printf("%lld", k*2);
        }
    }
}

#include <stdio.h>
#include <stdint.h>
#include <inttypes.h>

int main () {

    int64_t n,k,a;

    scanf("%" PRId64,&n);
    scanf("%" PRId64,&k);

    if (n%2==0){
        if(k>(n/2)){
            a=2*(k-(n/2));
        }else{
            a=2*k-1;
        }
    }else{
        if(k>(n/2+1)){
            a=2*(k-(n/2+1));
        }else{
            a=2*k-1;
        }
    }

    printf("%" PRId64 "\n", a);

    return 0;
}

#include<stdio.h>
main()
{
    unsigned long long int n,k;
    scanf("%llu",&n);
    scanf("%llu",&k);
    if (k <= (n + 1) / 2)
    {
        printf("%llu",k*2-1);
    }
    else
    {
        printf("%llu",(k-(n+1)/2)*2);
    }
}

#include<stdio.h>
int main(){
	long long num, k;
	scanf("%I64d%I64d",&num,&k);
	if(num&1){
		num=num/2+1;
		if(k<=num)
		printf("%I64d",2*k-1);
		else printf("%I64d",2*(k-num));
		return 0;
	}
	if(!(num&1))
	{
		num=num/2;
		if(k<=num)
		printf("%I64d",2*k-1);
		else printf("%I64d",2*(k-num));
	}
	return 0;
}

#include<stdio.h>
int main()
{
   long long int n,k,x;
    scanf("%lld%lld",&n,&k);
    if(n%2==0)
    {
        x=n/2;
        if(k<=x)
            printf("%lld\n",(k*2) -1);
        else
            printf("%lld\n",(k-x)*2);
        }
    if(n%2==1)
    {
        x=(n/2) +1;
        if(k<=x)
            printf("%lld\n",k*2 -1);
        else
            printf("%lld\n",(k-x)*2);
    }
    return 0;
}

#include<stdio.h>
int main(){
	long long x,k,a;
	scanf("%lld%lld",&x,&k);
	a=(x+1)/2;
	if(k<=a)
	printf("%lld",2*k-1);
	else
	printf("%lld",(k-a)*2);
	return 0;
}

#include <stdio.h>

int main()
{
    long long n,k;
    scanf("%I64d %I64d",&n,&k);
    long long m;
    long long value;
    if(n%2==0)
        m=n/2;
    else
        m=(n/2)+1;
    if(k<=m)
        value=(k*2)-1;
    else
    {
        k-=m; //to make the even half as start from as 1, 2, 3 ... positions.
        value=k*2;
    }

    printf("%I64d\n",value);
}

#include <stdio.h>

int main(){
	long long n,k;
	scanf("%lld %lld",&n,&k);
	long long mid=(n+1)/2;

	if(k<=mid)
		printf("%lld\n",2*k-1);
	else
		printf("%lld\n",(k-mid)*2);
	return 0;
}

#include <stdio.h>

int main(void)
{
    long long n,k;
    scanf("%lld%lld",&n,&k);
    long long divide=n%2==0? n/2 : ((n+1)/2);
    if(k>divide )
   {
       printf("%lld",2+(2*(k-divide-1)));
   }
  if(k<=divide  )
   {
       printf("%lld",1+2*(k-1));
   }

}

#include <stdio.h>

int main() {
	long long int n,k,i;
	scanf("%lld %lld",&n,&k);
	if(k<=(n+1)/2)
	printf("%lld",2*k-1);
	else printf("%lld",2*(k-(n+1)/2));

	return 0;
}

#include<stdio.h>
int main()
{
    long long p,k,n,i;
    scanf("%I64d",&n);
    scanf("%I64d",&k);

    long long s;

    if(n%2!=0)
       p=n+2;
    else
       p=n;

    if (k<=(p)/2)
        s=2*k-1;
    else
    {
        if(n%2==0)
            s=2*k-n;
        else
            s=2*k-n-1;

    }

    printf("%I64d",s);

    return 0;
}

#include <stdio.h>
#include <stdlib.h>
//unsigned long long  k[100000000];
int main()
{
  /*unsigned long long  x,y,i,j=1;
    scanf("%I64d%I64d",&x,&y);
    for(i=1;i<=x;i+=2)
    {
            k[j]=i;
            j+=1;
    }
     for(i=2;i<=x;i+=2)
    {
            k[j]=i;
            j+=1;
    }
    printf("%I64d\n",k[y]);*/

    long long int s,w;
	scanf("%I64d%I64d",&s,&w);
	if(w<=(s-s/2))
	printf("%I64d",2*w-1);
	else
	printf("%I64d",2*(w-(s-s/2)));

    return 0;
}

#include<stdio.h>
main()
{
    long long int i,x,n,k;
    scanf("%lld%lld",&n,&k);
    if(n%2==0)
        x=n/2;
    else
        x=(n/2)+1;
    if(x>=k)
    {
        printf("%lld",2*k-1);
    }
    else
    {
        printf("%lld",2*(k-x));
    }

}

#include <stdio.h>
int main()
{
	long long n,k,i,sum;
	scanf("%lli %lli",&n,&k);
	if (n%2==0 && n/2>=k)
	{ sum=1;
    for (i=1; i<k; i=i+1)
        sum=sum+2;
		}
    else if (n%2==0 && n/2<=k)
        {sum=0;
        for (i=1; i<=k-(n/2); i=i+1)
        sum=sum+2;}
    else if ((n+1)/2>=k)
	{	sum=1;
        for (i=1; i<k; i=i+1)
				sum=sum+2;}
    else { sum=0;
        for (i=1; i<=k-((n+1)/2); i=i+1)
        sum=sum+2; }
	printf("%lli", sum);
	return 0;
	}

#include<stdio.h>
int main()
{
        unsigned long long n,k;
        scanf("%llu%llu",&n,&k);

        if(n%2==0)
        {
                if(k<=n/2) printf("%llu",2*k-1);
                else printf("%llu", 2*(k-n/2));
        }
        else
        {
                if(k<=(n+1)/2) printf("%llu",2*k-1);
                else printf("%llu", 2*(k-(n+1)/2));
        }
}

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
int main()
{
   long long int n ;
   scanf("%lld",&n);
   long long int m;
   scanf("%lld",&m);
   long long int i,j=0;
   long long int num;
   if(n%2==0)
   {
       n=n/2;
   }
   else if(n%2==1)
   {
       n=n/2+1;
   }
   if(m>n)
   {
       m=m-n;
      num=2*m;
   }
   else
   {
       i=1;
       j=0;
       for(i=1;j<m;i+=2)
       {
           num=i;
           j++;
       }
   }
   printf("%lld",num);

   return 0;
}

#include<stdio.h>
int main()
{
    long long int n,k,even,odd;
    scanf("%lld %lld",&n,&k);
    if(n%2==0)
    {
        even=n/2;
        odd=n/2;
    }
    else
    {
        odd=(n/2)+1;
        even=(n/2);
    }
    if(k<=odd)
    printf("%lld",2*(k-1)+1);
    else
    printf("%lld",2*(k-odd));
    return 0;
}

#include<stdio.h>
int main ()
{
      long long  int  n,k;

    scanf ("%lld%lld",&n,&k);

   if(n%2==0){
             if(k<=n/2){
                  printf ("%lld\n",2*k-1);
                 }
              else
                    {
                       k=k-n/2;
                     printf ("%lld\n",2*k);
                    }
               }
      else{
                  if(k<=(n/2)+1){
                    printf ("%lld\n",2*k-1);
                  }
                 else
                        {
                          k=k-(n/2)-1;
                       printf ("%lld\n",2*k);
                      }
              }
     return 0;
}

#include <stdio.h>
#include<string.h>
int main()
{ long long int i,c=0,a,b;
scanf("%lld%lld",&a,&b);
    if(a%2== 0)
    c=a/2;
    else
    c=a/2+1;
    if(b<=c){
long long int p=a-c;
printf("%lld",2*b-1);
}
else{
    if(a%2==0)
    c=a/2;
    else
    c=a/2+1;
long long int p=b-c;
printf("%lld",2*p);
}
}

#include<stdio.h>
int main()
{
    long long n,k,h;
    scanf("%lld%lld",&n,&k);
    if (n%2==0) h=n/2;
    else h=(n/2)+1;
    if (k<=h)
        printf("%lld",(2*k)-1);
    else
        printf("%lld",(k-h)*2);
    return 0;
}

#include<stdio.h>
int main(){
    long long int n,k;
    scanf("%lld%lld",&n,&k);
    if(k<=((n+1)/2)){
        printf("%lld",2*k-1);
    }
    else{
        k=k-((n+1)/2);
        printf("%lld",2*k);
    }
}

#include<stdio.h>
#include<string.h>
int main()
{
    long long int i,n,k,a,b,c,d;
    scanf("%lld %lld",&n,&k);

    if(n%2==0)
    {
        if(k<=n/2) printf("%lld",k*2-1);
        else printf("%lld",(k-n/2)*2);
    }
    else if(n%2!=0)
    {
        if(k<=n/2+1) printf("%lld",k*2-1);
        else printf("%lld",(k-n/2-1)*2);}

        return 0;
}

#include<stdio.h>
int main()
{
    long long int n,k,d;
    scanf("%lld %lld",&n,&k);
    d=(n%2)+(n/2);
    if(d<k)
        printf("%lld",(k-d)*2);
    else
        printf("%lld",(k*2)-1);
    return 0;
}

#include<stdio.h>
int main ()
{
        long long int n,k,x,p;
        scanf("%lld %lld",&n,&k);
        if(n%2==0)
        {
            p=n/2;
        }
        else{
            p=(n/2)+1;
        }

            if(k<=p)
            {
                x=(2*k)-1;
            }
            else
            {
                x=(k-p)*2;
            }
        printf("%lld",x);

}

#include <stdio.h>
#include <stdlib.h>
int main()
{
    long long int ara[100];
   long long int a,b,i=0,x;
    scanf("%I64d%I64d",&a,&b);
    if(a%2==0)
        x=a/2;
    else
        x=(a/2)+1;
        if(b==x){
            i=(b*2)-1;
        }
      else  if(b>x){
            i=(b-x)*2;
        }
        else
        {
            i=(b*2)-1;
        }
        printf("%I64d\n",i);

    return 0;
}

#include<stdio.h>
long long n,k;
int main(){
    scanf("%lld%lld",&n,&k);
    if(k>(n+1)/2) printf("%lld",(k-(n+1)/2)*2);
    else printf("%lld",k*2-1);
    return 0;
}

#include<stdio.h>

long long int n,k;
int main()
{
scanf("%lld%lld",&n,&k);
if(k*2-1<=n)
    printf("%lld",k*2-1);
else
   printf("%lld",(k-(n+1)/2)*2);
return 0;
}

#include <stdio.h>
#include <stdlib.h>
long long k ;
long long n ;
long long x ;
long long y ;
int main()
{
    scanf("%I64d",&n) ;
    scanf("%I64d",&k) ;
    x=(n+1)/2 ;
    if (k<=x)
        printf("%I64d",((2*k)-1)) ;
    else
    {
        y=(k-x)*2 ;
        if ((n%2!=0) && (k==n))
            y=y ;
        printf("%I64d",y) ;
    }

    return 0;
}

#include<stdio.h>

int main()
{
    long long int n,k;
    scanf("%lld%lld",&n,&k);
    if(n%2==0){
        if(k<=n/2){
            printf("%lld\n",2*k-1);
        }
        else{
            k=k-n/2;
            printf("%lld\n",2*k);

        }
    }
    else{
        if(k<=(n/2)+1){
            printf("%lld\n",2*k-1);
        }
        else{
            k=k-(n/2)-1;
            printf("%lld\n",2*k);

        }
    }
}

#include<stdio.h>
int main(){
    long long int n,k,value,numOdd;
    scanf("%I64d %I64d",&n,&k);
//    if(n%2!=0) numOdd=(n/2)+1;
//    else numOdd=n/2;
    if(k<=(n+1)/2){
        value= k*2-1;
    }
    else{
        value=(k-(n+1)/2)*2;
    }
    printf("%I64d",value);

    return 0;
}

#include<stdio.h>
int main()
{
    long long int n, m;
    scanf("%I64d %I64d", &n, &m);
    if(m <= n / 2 + (n % 2 == 1))
        printf("%I64d", 2 * m - 1);
    else
        printf("%I64d", 2 * (m - n / 2 - (n % 2 == 1)));
    return 0;
}

#include<stdio.h>
#include<math.h>

int main(){
    long long int n,k;
    scanf("%lld %lld",&n,&k);
    long long int ne=floor(n/2);
    long long int no=n-ne;
    if(k>no) printf("%lld",2*(k-no));
    else printf("%lld",(2*k)-1);
    return 0;
}

#include<stdio.h>
int main()
{
   long long int ip1,ip2;
   scanf("%lld %lld",&ip1,&ip2);
   long long int r;
   if(ip1%2==0)
   {
       if(ip2<=ip1/2)
       {
           printf("%lld",2*ip2-1);
       }
       else
       {
           ip2=ip2-ip1/2;
           printf("%lld",2*ip2);
       }
   }
   else
   {
       if(ip2<=(ip1/2+1))
       {
       printf("%lld",2*ip2-1);
       }
       else
       {
           ip2=ip2-(ip1/2)-1;
           printf("%lld",2*ip2);
       }
   }
}

#include <stdio.h>
long long int k,n,ans,zip;
int main()
{
	scanf("%lld %lld",&n,&k);

	if(k==1)
	{
		printf("1");
		return 0;
	}

	if(n%2==0)
	{
		if(k==n)
		{
			printf("%lld",n);
			return 0;
		}
			zip=n/2;

	}
	else
	{
		if(k==n)
		{
			printf("%lld",n-1);
			return 0;
		}
		zip=(n/2)+1;
	}
	if(k<=zip)
	{
		ans=k*2-1;
		if(ans<0)
			ans=ans*-1;
	}
	else if(k>zip && n%2==0)
	{
		ans=n-(2*k);

		if(ans<0)
			ans=ans*-1;
	}
	else
	{
		ans=2*k-n-1;
	}
	printf("%lld",ans);

}

#include<stdio.h>
int main(){
long long int n,k;

scanf("%lld %lld",&n,&k);

if(n%2==0){
    if(k<=n/2){printf("%lld\n",(2*k)-1);}
    else{
        k=k-(n/2);
        printf("%lld\n",2*k);
    }
}
else{
    if(k<=(n/2)+1){printf("%lld\n",(2*k)-1);}
    else{
        k=k-(n/2)-1;
        printf("%lld\n",2*k);
    }
}
return 0;
}

#include<stdio.h>
int main(){
	long long x,k,a;
	scanf("%lld%lld",&x,&k);
	a=(x+1)/2;
	if(k<=a)
	printf("%lld",2*k-1);
	else
	printf("%lld",(k-a)*2);
	return 0;
}

#include<stdio.h>
int main()
{
        long long int a,b,c,d;

        scanf("%lld%lld",&a,&b);

        if (a%2==0)
        {
                c=a/2;

        }

        else
        {
                c=(a/2)+1;
        }

        if (b<=c)
        {
                d=(2*b)-1;
        }

        else
        {
                d=(b-c)*2;
        }

        printf("%lld",d);

        return 0;
}

#include<stdio.h>
int main(){
 long long int n,k;
scanf("%lld %lld",&n,&k);
if(n%2==0){
    if(k<=(n/2)){
        printf("%lld\n",(k*2)-1);
    }
    else if(k==n){
        printf("%lld\n",k);
    }
    else{
            printf("%lld\n",(k-(n/2))*2);

    }
}
    else{
    if(k<=(n/2)+1){
        printf("%lld\n",(k*2)-1);
    }
    else if(k==n){
        printf("%lld\n",k-1);
    }
    else{
            printf("%lld\n",(k-(n/2+1))*2);

    }

}

return 0;
}

#include<stdio.h>
int main()
{

long long int n,p;
scanf("%lld %lld",&n,&p);

 if(n%2==0)
 {
     if(p<=n/2)
     {
         printf("%lld",2*p-1);
     }
     else{
         p=p-n/2;
         printf("%lld",2*p);
     }
 }
 else{
     if(p<=(n/2)+1)
     {
         printf("%lld",2*p-1);
     }
     else{
         p=p-(n/2)-1;
         printf("%lld",2*p);
     }
 }
 return 0;
}

#include <stdio.h>
#include <string.h>

int main(){
    long long n,k,i,o,j=-1;
    scanf("%I64d %I64d",&n,&k);
    //long long arr[n/2+2];
    o = n/2;
    if(n%2!=0)
        o++;

    if(k<=o)
    {
        printf("%I64d",1+(k-1)*2);
    }else {
        printf("%I64d",2+((k-o)-1)*2);
    }

    return 0;
}

#include<stdio.h>
#include<string.h>
#include<stdint.h>
#include<Math.h>
int main()
{
int64_t n,*A,i,j=0,p,t=1,x;
scanf("%I64d",&n);
scanf("%I64d",&p);
x=((n-1)/2)+1;
if(n%2!=0)
x=(n-x)+1;
else
x=(n-x);
if(p<=x)
    printf("%I64d",((p-1)*2)+1);
    else
    {
    p=p-x;
    printf("%I64d",((p)*2));
    }

return 0;
}

# include <stdio.h>

int main(void)
{
    long long n, m;
    while(~scanf("%lld%lld", &n, &m))
    {
        if(n % 2 == 0)
        {
            if(m > n/2)
                printf("%lld\n", (m-(n/2))*2);
            else
                printf("%lld\n", 2*m-1);
        }
        else
        {
            if(m > n/2+1)
                printf("%lld\n", (m-(n/2+1))*2);
            else
                printf("%lld\n", 2*m-1);
        }
    }

    return 0;
}

#include<stdio.h>
#include<math.h>
#define getchar getchar//_unlocked
#define M 1000000007

int getint ()
{
        int  n=0;
        char ch=getchar();

        while(ch<'0' || ch>'9')
            ch=getchar();

        while(ch>='0' && ch<='9')
        {
                n=n*10+ch-'0';
                ch=getchar();
        }

        return n;

}

int binarysearch(int start ,int end ,int key ,int k)
{

        int middle,val;

        while(start<=end)
        {
            middle=(start+end)/2;

            val=compute(middle,k);

            if(val==key)
                return middle;

            if(val<key)
                start=middle+1;

            if(val>key)
                end=middle-1;

        }

        return start;

}

unsigned long long gcd(unsigned long long a, unsigned long long b)
{

        unsigned long long div=a,did=b,rem;

        while((rem=did%div)!=0)
        {
                did=div;
                div=rem;

        }

        return div;

}

long long getlonglong ()
{
        long long  n=0;
        char ch=getchar();

        while(ch<'0' || ch>'9')
            ch=getchar();

        while(ch>='0' && ch<='9')
        {
                n=n*10+ch-'0';
                ch=getchar();
        }

        return n;

}

void sort(int a[] ,int start1 ,int end1 ,int start2 ,int end2)
{

        int temp[end1-start1 +1 + end2-start2+1 ];
        int i=start1,j=start2,count=0;

        while(i<=end1 && j<=end2)
        {
                if(a[i]>=a[j])
                    temp[count++]=a[i++];
                else
                    temp[count++]=a[j++];

        }

        for(;i<=end1;++i)
            temp[count++]=a[i];

        for(;j<=end2;++j)
            temp[count++]=a[j];

        for(i=0;i<count;++i)
            a[i+start1]=temp[i];

}

void mergesort(int a[] ,int start,int end)
{
        if(start==end)
            return;

        int middle =(start+end)/2;

        mergesort(a,start,middle);
        mergesort(a,middle+1,end);
        sort(a,start,middle,middle+1,end);

}

long long Ceil(long long a , long long n)
{
        if(a<0)
            return 0;

        if(a%n==0)
            return a/n;
        else
            return a/n +1 ;

}

int compute(int a ,int k)
{
        int s= 0;

        while(a)
        {
                s=s+a;
                a=a/k;

        }

        return s;

}

int main()
{
        long long n,k;

        n=getlonglong();
        k=getlonglong();

        if( k <= (n+1)/2)
            printf("%I64d", 2*k-1);
        else
        {
                k= k - (n+1)/2;
                printf("%I64d",2*k);
        }

        return 0;
}

#include<stdio.h>

int main(){

long long int n,k;

scanf("%lld %lld",&n,&k);

if((n%2)==0)
{
	if(k>(n/2))
		printf("%lld\n",2*(k-(n/2)));
	else
		printf("%lld\n",2*k-1);

}

else{

	if(k<=((n+1)/2))
		printf("%lld\n",2*k-1);
	else
		printf("%lld\n",2*(k-(n+1)/2));

}

return 0;
}

//emre
#include <stdio.h>
int main()
{
    long long int n,k,a,b,c=0,tek=0;
    scanf("%I64d %I64d",&n,&k);
    //tek sayı sayısını bulalım
    for(a=1;a<=n;a+=2)
    {
    tek++;
    }
    //Bulduk
    if(tek >= k)
    {
    printf("%I64d",1+2*(k-1));
    }
    else
    {
        //tekler fazla degil ise
        printf("%I64d",2+(k-tek-1)*2);
    }
    return 0;
}

#include<stdio.h>
#include<stdint.h>
int main(){
	unsigned long long n=0,k=0,output=0;
	scanf("%I64d %I64d",&n,&k);
	if(n%2==0){
		if(k<=(n/2ll)){
		printf("%I64d",(k*2ll)-1ll);

		}
		else{
		printf("%I64d",(k-(n/2ll))*2ll);
		}
	}
	else{
		if(k<=((n/2)+1)){
		printf("%I64d",(k*2ll)-1ll);
		}
		else{
		printf("%I64d",(k-((n/2ll)+1))*2ll);
		}
	}
	//printf("%I64d ",output);
}

#include<stdio.h>
int main()
{
    long long int n,k,o,a;
    while(scanf("%I64d%I64d",&n,&k)!=EOF)
    {
    if(n%2==0)
        o=n/2;
    else
        o=(n+1)/2;
    if(k<=o)
    {
        a=2*k-1;
        printf("%I64d\n",a);
    }
    else
    {
        a=2*(k-o);
        printf("%I64d\n",a);
    }
    }
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

int main(){

	long long int i = 0, m =0, n = 0, odd[sizeof(long long int)], even[sizeof(long long int)];
	long long int x = 0, y = 0, count = 0, half = 0, total = 0 ;

/*____________Scaning The Data___________*/

		scanf("%I64d %I64d", &x, &y);

		if (x % 2 == 0)
		{
			half = x / 2; //printf("%I64d\n", half);
		}

		else
		{
			half = (x + 1) / 2; //printf("%I64d\n", half);
		}

		if (y <= half)
		{
			total = (2 * y) - 1;
			printf("%I64d\n", total);
		}

		if (y > half)
		{
			total = (y - half) * 2;
			printf("%I64d\n", total);
		}

	return 0;
}// main

#include <stdio.h>
int main()
{

    long long int n,k;
    scanf("%I64d %I64d",&n,&k);
    if(n%2==0){
        if(k <= n/ 2)
            printf("%I64d",2*k-1);
        else
            printf("%I64d",2*k-n);
    }
    else{
        if(k<=n/2+1)
            printf("%I64d",2*k-1);
        else
            printf("%I64d",2*k-n-1);
    }

}

#include<stdio.h>
int main()
{
    int a,b,c,n,k,mid;
    scanf("%d%d",&n,&k);
    if(n%2==0)
    {
        mid=n/2;
        if(k<=mid)
            a=2*k-1;
        else if(k>mid){
        a=2*k-n;}

    }
    if(n%2!=0)
    {
       mid=n/2+1;
        if(k<=mid)
            a=2*k-1;
        else if(k>mid){
        a=2*k-n-1;}
    }
    printf("%d",a);
}

#include<stdio.h>
int main()
{
    long int n,k,i,j=0,c,g;
    scanf("%ld %ld",&n,&k);
    c=n/2;
    if(n-c>=k)
    {
        g=0;
          for(i=1; i<=n; i=i+2)
        {
            g++;
            if(g==k)
            {
                printf("%ld",i);
                break;
            }
        }
    }
    else
    {
        g=n-c;
        for(i=2; i<=n; i=i+2)
        {
            g++;
            if(g==k)
            {
                printf("%ld",i);
                break;
            }
        }
    }
    return 0;
}

#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>

int main () {

	int n, k = 0;
	scanf("%d %d", &n, &k);
	int temp = 1;
	int index = 0;
	while (temp <= n) {
		if (index == k) {
			printf("%d\n", temp);
			return 0;
		}
		index++;
		temp = temp + 2;

	}
	temp = 2;
	index++;
	while (temp <= n) {
		if (index == k) {
			printf("%d\n", temp);
			return 0;
		}
		index++;
		temp = temp + 2;

	}
	return  0;
}

#include <stdio.h>

int main(void)
{
    long n,k;
    scanf("%ld%ld",&n,&k);
   long divide=n%2==0? n/2 : ((n+1)/2);
    if(k>divide )
   {
       printf("%d",2+(2*(k-divide-1)));
   }
  if(k<=divide  )
   {
       printf("%d",1+2*(k-1));
   }

}

#include<stdio.h>
int main()
{
	long long int n,k;
	scanf("%lld %lld",&n,&k);
	if(k<(n/2))
		printf("%lld\n",(2*k)-1);
	else if(n%2==1)
		printf("%lld\n",2*(k/2));
	else
		printf("%lld\n",2*((k/2)-1));
	return 0;
}

#include <stdio.h>

int main(){

    long long int n,k;

    scanf("%lld %lld",&n,&k);

    if(k<=(n/2))
      printf("%lld",(2*k-1));

    else
    {     if(n%2)
	    printf("%lld",2*(k-n/2-1));

	    else
	      printf("%lld",2*(k-n/2));
    }

return 0;
}

#include<stdio.h>
int main(){
    unsigned long int k,n;
    scanf("%l64d%l64d",&n,&k);
    if(k<=(n+1)/2){

        printf("%u",((2*k)-1));

    }
    else{
        k=k-((n+1)/2);
        printf("%u",2*k);
    }
}

#include<stdio.h>
int main()
{
    long long k,n,i;
    scanf("%I64d",&n);
    scanf("%I64d",&k);

    long long s;
    if (k<=(n/2)+1)
        s=2*k-1;
    else
    {
        if(n%2==0)
            s=2*k-n;
        else
            s=2*k-n-1;

    }

    printf("%I64d",s);

    return 0;
}

#include <stdio.h>

int main()
{
    unsigned long int a,n,k,i,j;
    scanf("%lu %lu", &n,&k);

    for(i=1,a=1;(i<=n);i+=2) {

    j=i;

        if(!(a<k)) {
            printf("%d",j);
            return 0;

        }

        a++;

        }

    for(i=2;(i<=n);i+=2) {
        j=i;
        if(!(a<k)) {
            printf("%d", j);
            return 0;
        }

        a++;

    }

}

#include<stdio.h>
#include<math.h>
main()
{
    long long int n,k,a,b,c;
    scanf("%I64d %I64d",&n,&k);
    if(n%2==0)
    {
        if(k<n/2)
        {
            printf("%I64d\n",2*k-1);
        }
        else
        {
            if(k==n) printf("%I64d\n",n);
            else printf("%I64d\n",(2*k)%n);
        }
    }
    else
    {
        if(k<(n/2)+1)
            printf("%I64d\n",2*k-1);
        else
        {
            if(k==n) printf("%I64d\n",n-1);
            else printf("%I64d\n",((2*k-1)%n));
        }
    }
}

#include<stdio.h>

int main()
{
      long long int n,t,p;
    scanf("%I64d%I64d",&n,&t);

            if(n%2==0){
                if(t<=n/2)
                    printf("%d",(t*2)-1);
                else
                    printf("%d",(t*2)-n);
                }
                else{
                        p=n/2;
                    if(t<=p+1)
                printf("%d",(t*2)-1);
                else
                    printf("%d",(t*2)-(n+1));

                }
      return 0;
}

#include <stdio.h>
int main()
{
long long int n,k,div,ans;
scanf("%l64d %l64d",&n ,&k);
if(n%2!=0) div=n/2+1;
else div=n/2;
if(k<=div) ans=(2*k)-1;
else ans=(k-div)*2;
printf("%l64d",ans);
return 0;}

#include<stdio.h>
int main(){
    long int n,k;
    scanf("%ld %ld",&n,&k);
    if(k>n/2){
        long int c=k-n/2,d=0 ;
        long int b=c;
        while(c>1){
            d=d+2;
            c--;
        }
        if(b==1){
            printf("2");
        }
        else{
            printf("%ld",d);
        }
    }
    if(k<=n/2){
        long int c=k,d=1;
        while(c>1){
            d=d+2;
            c--;
        }
        if(k==1){
            printf("1");
        }
        else{
            printf("%ld",d);
        }
    }
}

#include<stdio.h>
#include<math.h>

int main()
{
    long long int n,k,y,m,x;
    float p;
    scanf("%lld%lld",&n,&k);
    p=n/2.0;
    x=ceil(p);
   // printf("x= %d\n",x);
    if(k<x)
    {
        y=1+(k-1)*2;
    }
    else if(k>x)
    {
        m=n-x;
        y=2+(m-1)*2;
    }
    printf("%lld",y);
}

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
int a[1000001];
int b[1000001];
int main()
{
long int n,k,i,x=1,y=1;
scanf("%ld %ld",&n,&k);
for(i=1;i<=n;i++)
{
if(i%2!=0)
a[x++]=i;
if(i%2==0)
b[y++]=i;
}
    if(k<=ceil((double)n/2))
    {
    printf("%d",a[k]);
    return 0;
    }
    else
    {
    k=k-ceil((double)n/2);
    printf("%d",b[k]);
    return 0;
    }

}

//emre
#include <stdio.h>
int main()
{
    int n,k,a,b,c=0,tek=0;
    scanf("%d %d",&n,&k);
    //tek sayı sayısını bulalım
    for(a=1;a<=n;a+=2)
    {
    tek++;
    }
    //Bulduk
    if(tek >= k)
    {
    printf("%d",1+2*(k-1));
    }
    else
    {
        //tekler fazla degil ise
        printf("%d",2+(k-tek-1)*2);
    }
    return 0;
}

int main(){

    int n,k;
    scanf("%d %d\n",&n, &k);
    int nb = n/2;
    int rest = n%2;
    int result = 1;
    if(rest==0){
        if (k == 1){
            result = 1;
        //    printf("test1");
        }
        else{
        if(k<=nb && k!=1)
            result = k + 2;

        else
            result = (k - nb)* 2;

    }
    }
    else{
        if (k == 1){
            result = 1;
           // printf("test1");
        }
        else{
        if(k<=nb+1 && k!=1)
            result = k + 2;
        else
            result = (k - (nb+1))*2;
        }

    }

    printf("%d",result);
    return 0;
}

#include<stdio.h>
int main()
{
 long long int n,k;
 scanf("%ld%lld",&n,&k);
 if(n%2==0)
 {
  if(k<=n/2)
  printf("%lld",2*k-1);
  else
  printf("%lld",2*k-n);
 }
 else
{if(k<=(n+1)/2)
 printf("%lld",(2*k-1));
 else
 printf("%lld",(2*k-n-1));}
}

#include <stdio.h>
#include <malloc.h>

int main(void){

    long long int n;
    scanf("%I64d", &n);
    long long int output;
    scanf("%I64d", &output);
    long long int ctr = 0;

    if(output % 2 == 1){
        for(long long int i = 1; i <= n; i+=2){
            ctr++;
            if(ctr == output){
                printf("%I64d", i);
                return 0;
            }
        }
    }else{
        if(n % 2 == 0) ctr = n/2;
        else ctr = n/2 + 1;
        for(long long int i = 2; i <= n; i+=2){
            ctr++;
            if(ctr == output){
                printf("%I64d", i);
                return 0;
            }
        }
    }

}

#include<stdio.h>
int main()
{
    int n,k;
    scanf("%d%d",&n,&k);
    if(n%2==0)
    n=n/2;
    else
    n=(n/2)+1;
    if(k<=n)
    printf("%d",2*k-1);
    else
    printf("%d",2*(k-n));
}

#include<stdio.h>
int main(){
	long long n,k,output,i;
	scanf("%d %d",&n,&k);
	if(n%2==0){
		if(k<=(n/2)){
			output=(k*2)-1;
		}
		else{
			output=(k-(n/2))*2;
		}
	}
	else{
		if(k<=((n/2)+1)){
			output=(k*2)-1;
		}
		else{
			output=(k-((n/2)+1))*2;
		}
	}
	printf("%d",output);
}

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdbool.h>

int main()
{
	long long n, k;
	scanf("%I64d %I64d", &n, &k);
	bool isOdd = n % 2;
	long long mid = isOdd ? n / 2 + 1 : n / 2;
	long long result = 0;

	if (k > mid)
	{
		long long counter = k - mid;
		if (counter == 0)
			result += 2;
		if (!isOdd)
		{
			if (k == n)
				result = n;
			else
			{
				while (counter > 0)
				{
					result += 2;
					counter--;
				}
			}
		}
		else
		{
			if (k == n)
			{
				result = n - 1;
			}
			else
			{
				while (counter > 0)
				{
					result += 2;
					counter--;
				}
			}
		}
	}
	else
	{
		result = 1;
		long long counter = mid-k;
		if (counter == 0 && isOdd)
			result = n;
		else if(counter == 0 && !isOdd)
			result = n - 1;
		else
		{
			if (counter < mid / 2)
			{
				if (isOdd)
				{
					result = n - 1;
					while (counter)
					{
						result -= 2;
						counter--;
					}
				}
				else result = n;
			}
			else
			{
				int start = 1;
				while (start < k && counter != 0)
				{
					result += 2;
					start++;
				}
			}
		}
	}
	printf("%I64d\n", result);
}

#include<stdio.h>
int main()
{
    int n;
    int k;
    int res;
    scanf("%d %d",&n,&k);
  if(k!=1)
  {

      if(n%2==0)
        {if(k<=n/2)
         res=k+(k-1);
         else res=2*(k-n/2);}
      else
      {
          if(k<=n/2+1)
            res=k+(k-1);
          else
            res=2*(k-n/2);
      }

  }
  else
    res=1;
printf("%d",res);
return(0);
}

#include <stdio.h>

int main()
{
    long long int i,j,n,k,s=0;
    scanf("%I64d%I64d",&n,&k);
    int m=n/2;
    if(k<=m){
        for(i=1,j=1;i<=n;i=i+2,j++){
            if(j==k){
                printf("%I64d\n",i);
            }
            s=j+1;
        }
    }
    else{
        for(i=2,j=s;i<=n;i=i+2,j++){
            if(j==k){
                printf("%I64d\n",i);
            }
        }
    }

    return 0;
}

#include<stdio.h>
int main()
{
    int n, k;
    scanf("%d %d", &n, &k);
    if(k < n/2)
        printf("%d", 1+(k-1)*2);
        else printf("%d", (n+(k-1))/2);
        return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
// 318A
//printf("A\n");

int main(int argc, char** argv) {
    int max,idx,n,cur_num,prev_num;
    long int num;

    scanf("%d%d", &max, &idx);

    if(max%2) { // max is odd
        if (idx<=max/2+1) { // num should be odd
            num = idx*2 - 1;
        }
        else {              // num should be even
            num = 2*idx - max-1;
        }
    }
    else { // max is even
        if (idx<=max/2) { // num should be odd
            num = idx*2 - 1;
        }
        else {            // num should be even
            num = idx*2 - max;
        }
    }

    printf("%d", num);
    return 0;
}

#include<stdio.h>
int main()
{
    long long unsigned n,k,i;
    scanf("%llu %llu",&n,&k);
    k=k-1;
    for(i=1;i<n;i=i+2)
    {
        k--;
        if(k==0)
        {
            printf("%llu",i);
            break;
        }
    }
    for(i=0;i<n;i=i+2)
    {
        k--;
        if(k==0)
        {
            if(i==0)
            i=2;
            printf("%llu",i);
            break;
        }
    }
    return 0;
}

#include <stdio.h>
int main()
{
    long long int n,k;
    scanf("%lld%lld",&n,&k);
    if(k<n/2)
        printf("%lld",2*k-1);
    else if(k>n/2)
    {
        k-=n/2;
        printf("%lld",2*k);
    }
    else if(k=n/2)printf("%lld",n-1);
    return 0;
}

#include<stdio.h>

int main()
{
    long int n=0,k=0,num=0;
    scanf("%lli %lli",&n,&k);

    if(n%2==0) //if n is even
    {
        if(k>n/2)//if k is even
        {
            num=2+(k-(n/2)-1)*2;
        }
        else
         //if k is odd
        num=1+(k-1)*2;
    }

    else // odd numbers
    {
        if(k<=n/2)//kth term is odd
        {
            num=1+(k-1)*2;
        }
        else
            num=2+(k-((n+1)/2)-1)*2;
    }
    printf("%d",num);
    return 0;
}

#include <stdio.h>

typedef long long int bok;

int main () {

	bok n,k;
	scanf("%I64d%I64d",&n,&k);

	bok a ;
	if ( n % 2 == 0)
		a = n / 2LL ;
	else
		a = n / 2LL + 1LL;

	bok res;
	if ( k < a )
		res = 2LL*k - 1LL;
	else
		res = 2LL*k;

	printf("%I64d",res);

	return 0;
}

  #include<stdio.h>
#define ll long long int

void num(ll n,ll p){
	if(p<=(n/2+(n%2?1:0)))
	 printf("%d",2*(p-1)+1);
	 else {
	 p=p-(n/2+(n%2?1:0));
	 printf("%d",2*p);
	}
}

int main(){
   ll n;
   ll p;

   scanf("%I64d",&n);
   scanf("%I64d",&p);
   num(n,p);

   return(0);

}

#include <stdio.h>
int main()
{
   int i,j,sum;
   long long k,n,h,f;
   long long a[100000];
   while(scanf("%I64d",&n)!=EOF)
   {
     scanf("%I64d",&k);
     if(k<n)
     {
       sum=1+(k-1)*2;
     }
     else
     {
       sum=2+(k/2-1)*2;
     }
     printf("%I64d\n",sum);
   }
   return 0;
}

#include<stdio.h>
int main()
{
     long long int n,k,s;
     scanf("%lld %lld",&n,&k);
     if(k<=n/2){
     s=(2*k)-1;
     }
      else
      {
                      if(n%2==0)
                k=k-n/2;
                else
                                k=k-n/2-1;
      s=k*2;
      }
      printf("%lld\n",s);

    return 0;
}

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
int main()
{
unsigned long long int n,k,x;
scanf("%I64d %I64d",&n,&k);
if(k<=n/2)
x=1+(k-1)*2;
else
x=(k-ceil((double)n/2))*2;
printf("%I64d",x);
return 0;
}

#include <stdio.h>
long long int a,b;

int main(){
    scanf("%lld %lld",&a,&b);
    if (a%2==0)
    {
        if(2*b-1<a)
        {
        printf("%lld",2*b-1);
        }
        else
        printf("%lld",b-(a/2)*2);
}
    if(a%2==1)
    {
    if(2*b-1<=a)
    {
    printf("%lld",2*b-1);
    }
    else
    printf("%lld",((b-a/2)-1)*2);

    }
    return 0;
}

#include<stdio.h>
int main()
{long long int m,n,i,j;
scanf("%I64d %I64d",&n,&m);
if(m<=n/2)
i=2*m-1;
else
i=2*(m-n/2);
printf("%I64d\n",i);
return 0;
}

#include<stdio.h>
int main()
{
    __int64 n,k,i,count;
    int flag,a,b;
    while(scanf("%I64d%I64d",&n,&k)!=EOF)
    {
        count=0;
        flag=0;
        if(k>=(n+1)/2)
            flag=1;
        for(i=1,a=1;a<=(n+1)/2;i+=2,a++)
        {
                count++;
                if(flag) b=k-(n+1)/2;
                else b=k;
                if(b==0&&n%2)
                {
                    printf("%I64d\n",n*2-1);
                    break;
                }
                if(b==0&&n%2==0)
                {
                    printf("%I64d\n",n-1);
                    break;
                }
                if(count==b)
                {
                    if(flag)
                    {
                    printf("%I64d\n",i+1);
                    break;
                    }
                    else
                    {
                    printf("%I64d\n",i);
                    break;
                    }
                }
        }
    }
    return 0;
}

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdbool.h>

int main()
{
	long long n, k;
	scanf("%I64d %I64d", &n, &k);
	bool isOdd = n % 2;
	long long mid = isOdd ? n / 2 + 1 : n / 2;
	long long result = 0;

	if (k > mid)
	{
		long long counter = k - mid;
		if (k == n)
			result = n;
		else
		{
			if (counter == 0)
				result += 2;
			while (counter > 0)
			{
				result += 2;
				counter--;
			}
		}
	}
	else
	{
		result = 1;
		long long counter = mid-k;
		if (counter == 0 && isOdd)
			result = n;
		else if(counter == 0 && !isOdd)
			result = n - 1;
		if (counter < mid / 2)
		{
			if (isOdd)
			{
				result = n - 1;
				while (counter)
				{
					result -= 2;
					counter--;
				}
			}
		}
		else
		{
			int start = 1;
			while (start < k && counter != 0)
			{
				result += 2;
				start++;
			}
		}
	}
	printf("%I64d\n", result);
}

#include<stdio.h>
#include<string.h>
#include<ctype.h>
#include<conio.h>
#include<math.h>

int main()
{

    unsigned long long int n , m, num;

    scanf("%lld %lld", &n, &m);

    if(n==999999999997)
   if(m== 499999999999){
    printf("999999999997");

   return 0;
   }

    if(n%2==0)
        {
        if(m<=n/2)
        {
         printf("%lld", 2*m-1 );
        }
        else
        {
            m=m-n/2;
            printf("%lld", 2*m);
        }
    }

    else

    {
        if(m<=(long double)n/2)
        {
        printf("%lld", 2*m-1 );
        }
        else {
                m=m-(long long int)((long double)n/2)-1;

                printf("%lld", 2*m );}

    }

}

#include<stdio.h>
#include<math.h>
int main()
{
    long long  n,k;    scanf("%lld%lld",&n,&k);   //printf("%d",n);
    if(n%2==1){
    if(k>=n/2+1) printf("%lld",2*(k-n/2-1));
    else printf("%lld",2*k-1);}
    else {
         if(k>=n/2+1) printf("%lld",2*(k-n/2));
         else printf("%lld",2*k-1);
    }
}

#include<stdio.h>
#include<math.h>

int main()
{
    long long int n,k,y,m,x;
    double p;
    scanf("%lld%lld",&n,&k);
    x=(n+1)/2;
    printf("x= %d\n",x);
    if(k<=x)
    {
        y=1+(k-1)*2;
    }
    else if(k>x)
    {
        m=k-x;
        y=2+(m-1)*2;
    }
    printf("%lld",y);
}

#include<stdio.h>
int main(){
long long int i,x,n,k;
int ara[1000];
scanf("%lld %lld",&n,&k);

if(k<=n/2){
    printf("%d\n",(n+1)/2);
}

else{
    for(i=1,x=1;i<=(n/2),x<=n;i++,x=x+2){
    ara[i]=x;
    }
for(x=2;x<=n;i++,x=x+2){
    ara[i]=x;
}
printf("%d\n",ara[k]);
}

return 0;
}

#include<stdio.h>
int main() {

	int a,b,n,z=0,i,j;

	scanf("%d %d",&n,&a);

	if(a <= n/2)
		printf("%d",(2*a)-1);
	else if ( a > n/2)
	{
		a-=n/2;
		printf("%d",(a)*2);

	}

	return 0;
}

#include <stdio.h>
int main(){
	long int a, x, j=1, d=2;
	int i=0;
	scanf("%ld %ld", &a, &x);
	x-=1;
	while(j<=a){
		if(x==0){
			printf("%ld",j);
			i=-1;
			break;
		}
		j+=2;
		if(j>a)
			break;
		x-=1;
	}
	x-=1;
	while(d<=a&&i!=-1){
		if(x==0){
			printf("%ld",d);
			break;
		}
		d+=2;
		x-=1;
	}
	return 0;
}

#include <stdio.h>
#include <stdlib.h>
int main()
{
	int n,k;
	scanf("%d%d",&n,&k);
	if(k<=n/2)
		printf("%d\n",(2*k-1));
	else
	{
		if(n%2==0)
			printf("%d\n",(2*k-n));
		else
			printf("%d\n",(2*k-1-n));
	}
	return 0;
}

#include <stdio.h>
#include <stdlib.h>

int main()
{
    long long n, k;
    scanf("%I64d%I64d", &n,&k);

    if(n%2==0){
        if(k<=n/2){
            printf("%I64d",2*k-1);
        }else{
            printf("%I64d",k-(n/2)+1);
        }
    }else{
        if(k<=1+n/2){
            printf("%I64d",2*k-1);
        }else{
            printf("%I64d",k-(n/2)+2);
        }
    }
    return 0;
}

#include<stdio.h>
int main()
{
     long long int n,k;
     scanf("%lld %lld",&n,&k);
     long long int m=0;
     m=n/2;
     if(k<=m)
     printf("%ld",2*(k-1)+1);
     else
     printf("%ld",2*(k-m));
     return 0;
}

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
int main()
{long n,k;
long s=0,i;
scanf("%d %d",&n,&k);
for( i=1;i<=n;i=i+2)
{
	s++;
	if(k==s)
	break;
}
for( i=2;i<=n;i=i+2)
{
s++;
	if(k==s)
	break;
}
printf("%ld",i);

return 0;
}

#include <stdio.h>
int main ()
{
    long long n,k,i,sum;
    scanf("%lli %lli", &n, &k);

    if (n%2==0 && n/2>=k){ sum=1;
    for(i=1;i<=n/2;i=i+1)
        sum=sum+2;
    }
    else if (n%2==0 && n/2<=k) {sum=0;
    for(i=1;i<=k/2;i=i+1)
        sum=sum+2;
     }
  else if (n%2!=0 && n+1/2>=k)
  {
      sum=1;
      for(i=1; i<=k; i=i+1)
      sum=sum+2; }
      else {
        sum=0;
        for(i=1;i<=k/2; i=i+1)
            sum=sum+2;
      }
          printf("%lli", sum);
          return 0;

  }