package main

import (
	"bufio"
	"errors"
	"fmt"
	"io"
	"math"
	"os"
	"runtime"
	"strconv"
)

/*********** I/O ***********/

var (
	// ReadString returns a WORD string.
	ReadString func() string
	stdout     *bufio.Writer
)

func init() {
	var f *os.File
	if runtime.GOROOT() == "C:\\SOFT\\Go" {
		f, _ = os.Open("input.txt")
		//defer f.Close()
	} else {
		f = os.Stdin
	}
	ReadString = newReadString(f)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	// r.Buffer(make([]byte, 1024), int(1e+11)) // for AtCoder
	r.Buffer(make([]byte, 1024), int(1e+9)) // for Codeforces
	// Split sets the split function for the Scanner. The default split function is ScanLines.
	// Split panics if it is called after scanning has started.
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

// ReadInt returns an integer.
func ReadInt() int {
	return int(readInt64())
}
func ReadInt2() (int, int) {
	return int(readInt64()), int(readInt64())
}
func ReadInt3() (int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64())
}
func ReadInt4() (int, int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64()), int(readInt64())
}

// ReadInt64 returns as integer as int64.
func ReadInt64() int64 {
	return readInt64()
}
func ReadInt64_2() (int64, int64) {
	return readInt64(), readInt64()
}
func ReadInt64_3() (int64, int64, int64) {
	return readInt64(), readInt64(), readInt64()
}
func ReadInt64_4() (int64, int64, int64, int64) {
	return readInt64(), readInt64(), readInt64(), readInt64()
}

func readInt64() int64 {
	i, err := strconv.ParseInt(ReadString(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

// ReadIntSlice returns an integer slice that has n integers.
func ReadIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt()
	}
	return b
}

// ReadInt64Slice returns as int64 slice that has n integers.
func ReadInt64Slice(n int) []int64 {
	b := make([]int64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt64()
	}
	return b
}

// ReadFloat64 returns an float64.
func ReadFloat64() float64 {
	return float64(readFloat64())
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(ReadString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

// ReadFloatSlice returns an float64 slice that has n float64.
func ReadFloat64Slice(n int) []float64 {
	b := make([]float64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadFloat64()
	}
	return b
}

// ReadRuneSlice returns a rune slice.
func ReadRuneSlice() []rune {
	return []rune(ReadString())
}

/*********** Debugging ***********/

// ZeroPaddingRuneSlice returns binary expressions of integer n with zero padding.
// For debugging use.
func ZeroPaddingRuneSlice(n, digitsNum int) []rune {
	sn := fmt.Sprintf("%b", n)

	residualLength := digitsNum - len(sn)
	if residualLength <= 0 {
		return []rune(sn)
	}

	zeros := make([]rune, residualLength)
	for i := 0; i < len(zeros); i++ {
		zeros[i] = '0'
	}

	res := []rune{}
	res = append(res, zeros...)
	res = append(res, []rune(sn)...)

	return res
}

/*********** DP sub-functions ***********/

// ChMin accepts a pointer of integer and a target value.
// If target value is SMALLER than the first argument,
//	then the first argument will be updated by the second argument.
func ChMin(updatedValue *int, target int) bool {
	if *updatedValue > target {
		*updatedValue = target
		return true
	}
	return false
}

// ChMax accepts a pointer of integer and a target value.
// If target value is LARGER than the first argument,
//	then the first argument will be updated by the second argument.
func ChMax(updatedValue *int, target int) bool {
	if *updatedValue < target {
		*updatedValue = target
		return true
	}
	return false
}

// NthBit returns nth bit value of an argument.
// n starts from 0.
func NthBit(num, nth int) int {
	return num >> uint(nth) & 1
}

// OnBit returns the integer that has nth ON bit.
// If an argument has nth ON bit, OnBit returns the argument.
func OnBit(num, nth int) int {
	return num | (1 << uint(nth))
}

// OffBit returns the integer that has nth OFF bit.
// If an argument has nth OFF bit, OffBit returns the argument.
func OffBit(num, nth int) int {
	return num & ^(1 << uint(nth))
}

// PopCount returns the number of ON bit of an argument.
func PopCount(num int) int {
	res := 0

	for i := 0; i < 70; i++ {
		if ((num >> uint(i)) & 1) == 1 {
			res++
		}
	}

	return res
}

/*********** Arithmetic ***********/

// Max returns the max integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Max(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m < integer {
			m = integer
		}
	}
	return m
}

// Min returns the min integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Min(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m > integer {
			m = integer
		}
	}
	return m
}

// Sum returns multiple integers sum.
func Sum(integers ...int) int {
	s := 0

	for _, i := range integers {
		s += i
	}

	return s
}

// PowInt is integer version of math.Pow
// PowInt calculate a power by Binary Power (二分累乗法(O(log e))).
func PowInt(a, e int) int {
	if a < 0 || e < 0 {
		panic(errors.New("[argument error]: PowInt does not accept negative integers"))
	}

	if e == 0 {
		return 1
	}

	if e%2 == 0 {
		halfE := e / 2
		half := PowInt(a, halfE)
		return half * half
	}

	return a * PowInt(a, e-1)
}

// AbsInt is integer version of math.Abs
func AbsInt(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

// Gcd returns the Greatest Common Divisor of two natural numbers.
// Gcd only accepts two natural numbers (a, b >= 1).
// 0 or negative number causes panic.
// Gcd uses the Euclidean Algorithm.
func Gcd(a, b int) int {
	if a <= 0 || b <= 0 {
		panic(errors.New("[argument error]: Gcd only accepts two NATURAL numbers"))
	}
	if a < b {
		a, b = b, a
	}

	// Euclidean Algorithm
	for b > 0 {
		div := a % b
		a, b = b, div
	}

	return a
}

// Lcm returns the Least Common Multiple of two natural numbers.
// Lcd only accepts two natural numbers (a, b >= 1).
// 0 or negative number causes panic.
// Lcd uses the Euclidean Algorithm indirectly.
func Lcm(a, b int) int {
	if a <= 0 || b <= 0 {
		panic(errors.New("[argument error]: Gcd only accepts two NATURAL numbers"))
	}

	// a = a'*gcd, b = b'*gcd, a*b = a'*b'*gcd^2
	// a' and b' are relatively prime numbers
	// gcd consists of prime numbers, that are included in a and b
	gcd := Gcd(a, b)

	// not (a * b / gcd), because of reducing a probability of overflow
	return (a / gcd) * b
}

// Strtoi is a wrapper of strconv.Atoi().
// If strconv.Atoi() returns an error, Strtoi calls panic.
func Strtoi(s string) int {
	if i, err := strconv.Atoi(s); err != nil {
		panic(errors.New("[argument error]: Strtoi only accepts integer string"))
	} else {
		return i
	}
}

// PrintIntsLine returns integers string delimited by a space.
func PrintIntsLine(A ...int) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.Itoa(A[i])
		// str := strconv.FormatInt(A[i], 10)  // 64bit int version
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

/********** FAU standard libraries **********/

//fmt.Sprintf("%b\n", 255) 	// binary expression

/********** I/O usage **********/

//str := ReadString()
//i := ReadInt()
//X := ReadIntSlice(n)
//S := ReadRuneSlice()
//a := ReadFloat64()
//A := ReadFloat64Slice(n)

//str := ZeroPaddingRuneSlice(num, 32)
//str := PrintIntsLine(X...)

/*******************************************************************/

const MOD = 1000000000 + 7
const ALPHABET_NUM = 26
const INF_INT64 = math.MaxInt64
const INF_BIT60 = 1 << 60

func solve() {
	n := ReadInt()
	q := ReadIntSlice(n)
	p := make([]int, n)
	nums := make(map[int]int,n)
	p[0]=q[0]
	nums[q[0]]++
	start:=0
	for i := 1; i < n; i++ {
		qq := q[i]
		if qq > q[i-1] {
			p[i] = qq
			nums[qq]++
			continue
		}
		has :=  false
		for k:=start+1; k<qq;k++ {
			if _, ok := nums[k]; !ok {
				p[i] = k
				nums[k]++
				has= true
				start=k
				break
			}
		}
		if !has {
			fmt.Println(-1)
			return
		}
	}
	fmt.Println(PrintIntsLine(p...))
}

func main() {
	t := ReadInt()
	//t :=1
	for ; t > 0; t-- {
		solve()
	}
}

package main

import (
	"bufio"
	"errors"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
)

/*********** I/O ***********/

var (
	// ReadString returns a WORD string.
	ReadString func() string
	stdout     *bufio.Writer
)

func init() {
	ReadString = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	// r.Buffer(make([]byte, 1024), int(1e+11)) // for AtCoder
	r.Buffer(make([]byte, 1024), int(1e+9)) // for Codeforces
	// Split sets the split function for the Scanner. The default split function is ScanLines.
	// Split panics if it is called after scanning has started.
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

// ReadInt returns an integer.
func ReadInt() int {
	return int(readInt64())
}
func ReadInt2() (int, int) {
	return int(readInt64()), int(readInt64())
}
func ReadInt3() (int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64())
}
func ReadInt4() (int, int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64()), int(readInt64())
}

// ReadInt64 returns as integer as int64.
func ReadInt64() int64 {
	return readInt64()
}
func ReadInt64_2() (int64, int64) {
	return readInt64(), readInt64()
}
func ReadInt64_3() (int64, int64, int64) {
	return readInt64(), readInt64(), readInt64()
}
func ReadInt64_4() (int64, int64, int64, int64) {
	return readInt64(), readInt64(), readInt64(), readInt64()
}

func readInt64() int64 {
	i, err := strconv.ParseInt(ReadString(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

// ReadIntSlice returns an integer slice that has n integers.
func ReadIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt()
	}
	return b
}

// ReadInt64Slice returns as int64 slice that has n integers.
func ReadInt64Slice(n int) []int64 {
	b := make([]int64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt64()
	}
	return b
}

// ReadFloat64 returns an float64.
func ReadFloat64() float64 {
	return float64(readFloat64())
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(ReadString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

// ReadFloatSlice returns an float64 slice that has n float64.
func ReadFloat64Slice(n int) []float64 {
	b := make([]float64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadFloat64()
	}
	return b
}

// ReadRuneSlice returns a rune slice.
func ReadRuneSlice() []rune {
	return []rune(ReadString())
}

/*********** Debugging ***********/

// ZeroPaddingRuneSlice returns binary expressions of integer n with zero padding.
// For debugging use.
func ZeroPaddingRuneSlice(n, digitsNum int) []rune {
	sn := fmt.Sprintf("%b", n)

	residualLength := digitsNum - len(sn)
	if residualLength <= 0 {
		return []rune(sn)
	}

	zeros := make([]rune, residualLength)
	for i := 0; i < len(zeros); i++ {
		zeros[i] = '0'
	}

	res := []rune{}
	res = append(res, zeros...)
	res = append(res, []rune(sn)...)

	return res
}

/*********** DP sub-functions ***********/

// ChMin accepts a pointer of integer and a target value.
// If target value is SMALLER than the first argument,
//	then the first argument will be updated by the second argument.
func ChMin(updatedValue *int, target int) bool {
	if *updatedValue > target {
		*updatedValue = target
		return true
	}
	return false
}

// ChMax accepts a pointer of integer and a target value.
// If target value is LARGER than the first argument,
//	then the first argument will be updated by the second argument.
func ChMax(updatedValue *int, target int) bool {
	if *updatedValue < target {
		*updatedValue = target
		return true
	}
	return false
}

// NthBit returns nth bit value of an argument.
// n starts from 0.
func NthBit(num, nth int) int {
	return num >> uint(nth) & 1
}

// OnBit returns the integer that has nth ON bit.
// If an argument has nth ON bit, OnBit returns the argument.
func OnBit(num, nth int) int {
	return num | (1 << uint(nth))
}

// OffBit returns the integer that has nth OFF bit.
// If an argument has nth OFF bit, OffBit returns the argument.
func OffBit(num, nth int) int {
	return num & ^(1 << uint(nth))
}

// PopCount returns the number of ON bit of an argument.
func PopCount(num int) int {
	res := 0

	for i := 0; i < 70; i++ {
		if ((num >> uint(i)) & 1) == 1 {
			res++
		}
	}

	return res
}

/*********** Arithmetic ***********/

// Max returns the max integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Max(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m < integer {
			m = integer
		}
	}
	return m
}

// Min returns the min integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Min(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m > integer {
			m = integer
		}
	}
	return m
}

// Sum returns multiple integers sum.
func Sum(integers ...int) int {
	s := 0

	for _, i := range integers {
		s += i
	}

	return s
}

// PowInt is integer version of math.Pow
// PowInt calculate a power by Binary Power (二分累乗法(O(log e))).
func PowInt(a, e int) int {
	if a < 0 || e < 0 {
		panic(errors.New("[argument error]: PowInt does not accept negative integers"))
	}

	if e == 0 {
		return 1
	}

	if e%2 == 0 {
		halfE := e / 2
		half := PowInt(a, halfE)
		return half * half
	}

	return a * PowInt(a, e-1)
}

// AbsInt is integer version of math.Abs
func AbsInt(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

// Gcd returns the Greatest Common Divisor of two natural numbers.
// Gcd only accepts two natural numbers (a, b >= 1).
// 0 or negative number causes panic.
// Gcd uses the Euclidean Algorithm.
func Gcd(a, b int) int {
	if a <= 0 || b <= 0 {
		panic(errors.New("[argument error]: Gcd only accepts two NATURAL numbers"))
	}
	if a < b {
		a, b = b, a
	}

	// Euclidean Algorithm
	for b > 0 {
		div := a % b
		a, b = b, div
	}

	return a
}

// Lcm returns the Least Common Multiple of two natural numbers.
// Lcd only accepts two natural numbers (a, b >= 1).
// 0 or negative number causes panic.
// Lcd uses the Euclidean Algorithm indirectly.
func Lcm(a, b int) int {
	if a <= 0 || b <= 0 {
		panic(errors.New("[argument error]: Gcd only accepts two NATURAL numbers"))
	}

	// a = a'*gcd, b = b'*gcd, a*b = a'*b'*gcd^2
	// a' and b' are relatively prime numbers
	// gcd consists of prime numbers, that are included in a and b
	gcd := Gcd(a, b)

	// not (a * b / gcd), because of reducing a probability of overflow
	return (a / gcd) * b
}

// Strtoi is a wrapper of strconv.Atoi().
// If strconv.Atoi() returns an error, Strtoi calls panic.
func Strtoi(s string) int {
	if i, err := strconv.Atoi(s); err != nil {
		panic(errors.New("[argument error]: Strtoi only accepts integer string"))
	} else {
		return i
	}
}

// PrintIntsLine returns integers string delimited by a space.
func PrintIntsLine(A ...int) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.Itoa(A[i])
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

// PrintIntsLine returns integers string delimited by a space.
func PrintInts64Line(A ...int64) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.FormatInt(A[i], 10) // 64bit int version
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

/********** FAU standard libraries **********/

//fmt.Sprintf("%b\n", 255) 	// binary expression

/********** I/O usage **********/

//str := ReadString()
//i := ReadInt()
//X := ReadIntSlice(n)
//S := ReadRuneSlice()
//a := ReadFloat64()
//A := ReadFloat64Slice(n)

//str := ZeroPaddingRuneSlice(num, 32)
//str := PrintIntsLine(X...)

/*******************************************************************/

const MOD = 1000000000 + 7
const ALPHABET_NUM = 26
const INF_INT64 = math.MaxInt64
const INF_BIT60 = 1 << 60

var t int
var n int
var Q []int

func main() {
	t = ReadInt()

	for tc := 0; tc < t; tc++ {
		n = ReadInt()
		Q = ReadIntSlice(n)

		solve()
	}
}

func solve() {
	memo := make([]int, n+1)
	for i := 1; i <= n; i++ {
		memo[i] = 1
	}

	answers := make([]int, n)
	answers[0] = Q[0]
	memo[Q[0]] = 0
	for i := 1; i < n; i++ {
		if Q[i-1] < Q[i] {
			answers[i] = Q[i]
			memo[Q[i]] = 0
		}
	}

	c := 1
	for i := 0; i < n; i++ {
		// 未割り当てならば、小さいものを割り当てる、矛盾したらアウト
		if answers[i] == 0 {
			for c <= n {
				if memo[c] == 1 {
					if Q[i] >= c {
						answers[i] = c
						c++
						break
					} else {
						fmt.Println(-1)
						return
					}
				}
				// 次の未割り当ての小さい数字まですすめる
				c++
			}
		}
	}

	fmt.Println(PrintIntsLine(answers...))
}

/*
- MODは最後にとりましたか？
- ループを抜けた後も処理が必要じゃありませんか？
- 和・積・あまりを求められたらint64が必要ではありませんか？
*/

/*******************************************************************/

package main

import (
	"bufio"
	"errors"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
)

/*********** I/O ***********/

var (
	// ReadString returns a WORD string.
	ReadString func() string
	stdout     *bufio.Writer
)

func init() {
	ReadString = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	// r.Buffer(make([]byte, 1024), int(1e+11)) // for AtCoder
	r.Buffer(make([]byte, 1024), int(1e+9)) // for Codeforces
	// Split sets the split function for the Scanner. The default split function is ScanLines.
	// Split panics if it is called after scanning has started.
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

// ReadInt returns an integer.
func ReadInt() int {
	return int(readInt64())
}
func ReadInt2() (int, int) {
	return int(readInt64()), int(readInt64())
}
func ReadInt3() (int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64())
}
func ReadInt4() (int, int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64()), int(readInt64())
}

// ReadInt64 returns as integer as int64.
func ReadInt64() int64 {
	return readInt64()
}
func ReadInt64_2() (int64, int64) {
	return readInt64(), readInt64()
}
func ReadInt64_3() (int64, int64, int64) {
	return readInt64(), readInt64(), readInt64()
}
func ReadInt64_4() (int64, int64, int64, int64) {
	return readInt64(), readInt64(), readInt64(), readInt64()
}

func readInt64() int64 {
	i, err := strconv.ParseInt(ReadString(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

// ReadIntSlice returns an integer slice that has n integers.
func ReadIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt()
	}
	return b
}

// ReadInt64Slice returns as int64 slice that has n integers.
func ReadInt64Slice(n int) []int64 {
	b := make([]int64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt64()
	}
	return b
}

// ReadFloat64 returns an float64.
func ReadFloat64() float64 {
	return float64(readFloat64())
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(ReadString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

// ReadFloatSlice returns an float64 slice that has n float64.
func ReadFloat64Slice(n int) []float64 {
	b := make([]float64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadFloat64()
	}
	return b
}

// ReadRuneSlice returns a rune slice.
func ReadRuneSlice() []rune {
	return []rune(ReadString())
}

/*********** Debugging ***********/

// ZeroPaddingRuneSlice returns binary expressions of integer n with zero padding.
// For debugging use.
func ZeroPaddingRuneSlice(n, digitsNum int) []rune {
	sn := fmt.Sprintf("%b", n)

	residualLength := digitsNum - len(sn)
	if residualLength <= 0 {
		return []rune(sn)
	}

	zeros := make([]rune, residualLength)
	for i := 0; i < len(zeros); i++ {
		zeros[i] = '0'
	}

	res := []rune{}
	res = append(res, zeros...)
	res = append(res, []rune(sn)...)

	return res
}

/*********** DP sub-functions ***********/

// ChMin accepts a pointer of integer and a target value.
// If target value is SMALLER than the first argument,
//	then the first argument will be updated by the second argument.
func ChMin(updatedValue *int, target int) bool {
	if *updatedValue > target {
		*updatedValue = target
		return true
	}
	return false
}

// ChMax accepts a pointer of integer and a target value.
// If target value is LARGER than the first argument,
//	then the first argument will be updated by the second argument.
func ChMax(updatedValue *int, target int) bool {
	if *updatedValue < target {
		*updatedValue = target
		return true
	}
	return false
}

// NthBit returns nth bit value of an argument.
// n starts from 0.
func NthBit(num, nth int) int {
	return num >> uint(nth) & 1
}

// OnBit returns the integer that has nth ON bit.
// If an argument has nth ON bit, OnBit returns the argument.
func OnBit(num, nth int) int {
	return num | (1 << uint(nth))
}

// OffBit returns the integer that has nth OFF bit.
// If an argument has nth OFF bit, OffBit returns the argument.
func OffBit(num, nth int) int {
	return num & ^(1 << uint(nth))
}

// PopCount returns the number of ON bit of an argument.
func PopCount(num int) int {
	res := 0

	for i := 0; i < 70; i++ {
		if ((num >> uint(i)) & 1) == 1 {
			res++
		}
	}

	return res
}

/*********** Arithmetic ***********/

// Max returns the max integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Max(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m < integer {
			m = integer
		}
	}
	return m
}

// Min returns the min integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Min(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m > integer {
			m = integer
		}
	}
	return m
}

// Sum returns multiple integers sum.
func Sum(integers ...int) int {
	s := 0

	for _, i := range integers {
		s += i
	}

	return s
}

// PowInt is integer version of math.Pow
// PowInt calculate a power by Binary Power (二分累乗法(O(log e))).
func PowInt(a, e int) int {
	if a < 0 || e < 0 {
		panic(errors.New("[argument error]: PowInt does not accept negative integers"))
	}

	if e == 0 {
		return 1
	}

	if e%2 == 0 {
		halfE := e / 2
		half := PowInt(a, halfE)
		return half * half
	}

	return a * PowInt(a, e-1)
}

// AbsInt is integer version of math.Abs
func AbsInt(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

// Gcd returns the Greatest Common Divisor of two natural numbers.
// Gcd only accepts two natural numbers (a, b >= 1).
// 0 or negative number causes panic.
// Gcd uses the Euclidean Algorithm.
func Gcd(a, b int) int {
	if a <= 0 || b <= 0 {
		panic(errors.New("[argument error]: Gcd only accepts two NATURAL numbers"))
	}
	if a < b {
		a, b = b, a
	}

	// Euclidean Algorithm
	for b > 0 {
		div := a % b
		a, b = b, div
	}

	return a
}

// Lcm returns the Least Common Multiple of two natural numbers.
// Lcd only accepts two natural numbers (a, b >= 1).
// 0 or negative number causes panic.
// Lcd uses the Euclidean Algorithm indirectly.
func Lcm(a, b int) int {
	if a <= 0 || b <= 0 {
		panic(errors.New("[argument error]: Gcd only accepts two NATURAL numbers"))
	}

	// a = a'*gcd, b = b'*gcd, a*b = a'*b'*gcd^2
	// a' and b' are relatively prime numbers
	// gcd consists of prime numbers, that are included in a and b
	gcd := Gcd(a, b)

	// not (a * b / gcd), because of reducing a probability of overflow
	return (a / gcd) * b
}

// Strtoi is a wrapper of strconv.Atoi().
// If strconv.Atoi() returns an error, Strtoi calls panic.
func Strtoi(s string) int {
	if i, err := strconv.Atoi(s); err != nil {
		panic(errors.New("[argument error]: Strtoi only accepts integer string"))
	} else {
		return i
	}
}

// PrintIntsLine returns integers string delimited by a space.
func PrintIntsLine(A ...int) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.Itoa(A[i])
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

// PrintIntsLine returns integers string delimited by a space.
func PrintInts64Line(A ...int64) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.FormatInt(A[i], 10) // 64bit int version
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

/********** FAU standard libraries **********/

//fmt.Sprintf("%b\n", 255) 	// binary expression

/********** I/O usage **********/

//str := ReadString()
//i := ReadInt()
//X := ReadIntSlice(n)
//S := ReadRuneSlice()
//a := ReadFloat64()
//A := ReadFloat64Slice(n)

//str := ZeroPaddingRuneSlice(num, 32)
//str := PrintIntsLine(X...)

/*******************************************************************/

const MOD = 1000000000 + 7
const ALPHABET_NUM = 26
const INF_INT64 = math.MaxInt64
const INF_BIT60 = 1 << 60

var t int
var n int
var Q []int

func main() {
	t = ReadInt()

	for tc := 0; tc < t; tc++ {
		n = ReadInt()
		Q = ReadIntSlice(n)

		solve()
	}
}

func solve() {
	memo := make([]int, n+1)
	for i := 1; i <= n; i++ {
		memo[i] = 1
	}

	answers := make([]int, n)
	answers[0] = Q[0]
	memo[Q[0]] = 0
	for i := 1; i < n; i++ {
		if Q[i-1] < Q[i] {
			answers[i] = Q[i]
			memo[Q[i]] = 0
		}
	}

	// 未使用のものを小さい順にスライスに詰める
	unused := []int{}
	for i := 1; i <= n; i++ {
		if memo[i] == 1 {
			unused = append(unused, i)
		}
	}

	for i := 0; i < n; i++ {
		// 未割り当てならば、小さいものを割り当てる、矛盾したらアウト
		if answers[i] == 0 {
			// 次の未使用のものを取り出す
			c := unused[0]
			unused = unused[1:]
			if Q[i] >= c {
				answers[i] = c
			} else {
				fmt.Println(-1)
				return
			}
		}
	}

	// c := 1
	// for i := 0; i < n; i++ {
	// 	// 未割り当てならば、小さいものを割り当てる、矛盾したらアウト
	// 	if answers[i] == 0 {
	// 		for c <= n {
	// 			if memo[c] == 1 {
	// 				if Q[i] >= c {
	// 					answers[i] = c
	// 					c++
	// 					break
	// 				} else {
	// 					fmt.Println(-1)
	// 					return
	// 				}
	// 			}
	// 			// 次の未割り当ての小さい数字まですすめる
	// 			c++
	// 		}
	// 	}
	// }

	fmt.Println(PrintIntsLine(answers...))
}

/*
- MODは最後にとりましたか？
- ループを抜けた後も処理が必要じゃありませんか？
- 和・積・あまりを求められたらint64が必要ではありませんか？
*/

/*******************************************************************/

package main

import (
	"bufio"
	. "fmt"
	"io"
	"os"
)

func solve(reader io.Reader, writer io.Writer) {
	in := bufio.NewReader(reader)
	out := bufio.NewWriter(writer)
	defer out.Flush()

	var t int
outer:
	for Fscan(in, &t); t > 0; t-- {
		var n int
		Fscan(in, &n)
		a := make([]int, n)
		for i := range a {
			Fscan(in, &a[i])
		}
		ans := make([]int, n)
		vis := make([]bool, n+1)
		vis[a[0]] = true
		ans[0] = a[0]
		for i := 1; i < n; i++ {
			ai := a[i]
			if ai > a[i-1] {
				ans[i] = ai
				vis[ai]=true
			}
		}
		j := 1
		for i := range ans {
			if ans[i] == 0 {
				for ; j < n; j++ {
					if !vis[j] {
						ans[i] = j
						j++
						break
					}
				}
				if ans[i] == 0 {
					Fprintln(out, -1)
					continue outer
				}
			}
		}
		maxv := ans[0]
		for i, ai := range a {
			maxv = max(maxv, ans[i])
			if ai != maxv {
				Fprintln(out, -1)
				continue outer
			}
		}

		for _,ai := range ans {
			Fprint(out, ai, " ")
		}
		Fprintln(out)
	}

}

func main() {
	solve(os.Stdin, os.Stdout)
}

func ifElseI(cond bool, a, b int) int {
	if cond {
		return a
	}
	return b
}
func ifElseS(cond bool, a, b string) string {
	if cond {
		return a
	}
	return b
}
func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}
func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

package main

import (
	"bufio"
	"errors"
	"fmt"
	"io"
	"math"
	"os"
	"runtime"
	"strconv"
)

/*********** I/O ***********/

var (
	// ReadString returns a WORD string.
	ReadString func() string
	stdout     *bufio.Writer
)

func init() {
	var f *os.File
	if runtime.GOROOT() == "C:\\SOFT\\Go" {
		f, _ = os.Open("input.txt")
		//defer f.Close()
	} else {
		f = os.Stdin
	}
	ReadString = newReadString(f)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	// r.Buffer(make([]byte, 1024), int(1e+11)) // for AtCoder
	r.Buffer(make([]byte, 1024), int(1e+9)) // for Codeforces
	// Split sets the split function for the Scanner. The default split function is ScanLines.
	// Split panics if it is called after scanning has started.
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

// ReadInt returns an integer.
func ReadInt() int {
	return int(readInt64())
}
func ReadInt2() (int, int) {
	return int(readInt64()), int(readInt64())
}
func ReadInt3() (int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64())
}
func ReadInt4() (int, int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64()), int(readInt64())
}

// ReadInt64 returns as integer as int64.
func ReadInt64() int64 {
	return readInt64()
}
func ReadInt64_2() (int64, int64) {
	return readInt64(), readInt64()
}
func ReadInt64_3() (int64, int64, int64) {
	return readInt64(), readInt64(), readInt64()
}
func ReadInt64_4() (int64, int64, int64, int64) {
	return readInt64(), readInt64(), readInt64(), readInt64()
}

func readInt64() int64 {
	i, err := strconv.ParseInt(ReadString(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

// ReadIntSlice returns an integer slice that has n integers.
func ReadIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt()
	}
	return b
}

// ReadInt64Slice returns as int64 slice that has n integers.
func ReadInt64Slice(n int) []int64 {
	b := make([]int64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt64()
	}
	return b
}

// ReadFloat64 returns an float64.
func ReadFloat64() float64 {
	return float64(readFloat64())
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(ReadString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

// ReadFloatSlice returns an float64 slice that has n float64.
func ReadFloat64Slice(n int) []float64 {
	b := make([]float64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadFloat64()
	}
	return b
}

// ReadRuneSlice returns a rune slice.
func ReadRuneSlice() []rune {
	return []rune(ReadString())
}

/*********** Debugging ***********/

// ZeroPaddingRuneSlice returns binary expressions of integer n with zero padding.
// For debugging use.
func ZeroPaddingRuneSlice(n, digitsNum int) []rune {
	sn := fmt.Sprintf("%b", n)

	residualLength := digitsNum - len(sn)
	if residualLength <= 0 {
		return []rune(sn)
	}

	zeros := make([]rune, residualLength)
	for i := 0; i < len(zeros); i++ {
		zeros[i] = '0'
	}

	res := []rune{}
	res = append(res, zeros...)
	res = append(res, []rune(sn)...)

	return res
}

/*********** DP sub-functions ***********/

// ChMin accepts a pointer of integer and a target value.
// If target value is SMALLER than the first argument,
//	then the first argument will be updated by the second argument.
func ChMin(updatedValue *int, target int) bool {
	if *updatedValue > target {
		*updatedValue = target
		return true
	}
	return false
}

// ChMax accepts a pointer of integer and a target value.
// If target value is LARGER than the first argument,
//	then the first argument will be updated by the second argument.
func ChMax(updatedValue *int, target int) bool {
	if *updatedValue < target {
		*updatedValue = target
		return true
	}
	return false
}

// NthBit returns nth bit value of an argument.
// n starts from 0.
func NthBit(num, nth int) int {
	return num >> uint(nth) & 1
}

// OnBit returns the integer that has nth ON bit.
// If an argument has nth ON bit, OnBit returns the argument.
func OnBit(num, nth int) int {
	return num | (1 << uint(nth))
}

// OffBit returns the integer that has nth OFF bit.
// If an argument has nth OFF bit, OffBit returns the argument.
func OffBit(num, nth int) int {
	return num & ^(1 << uint(nth))
}

// PopCount returns the number of ON bit of an argument.
func PopCount(num int) int {
	res := 0

	for i := 0; i < 70; i++ {
		if ((num >> uint(i)) & 1) == 1 {
			res++
		}
	}

	return res
}

/*********** Arithmetic ***********/

// Max returns the max integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Max(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m < integer {
			m = integer
		}
	}
	return m
}

// Min returns the min integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Min(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m > integer {
			m = integer
		}
	}
	return m
}

// Sum returns multiple integers sum.
func Sum(integers ...int) int {
	s := 0

	for _, i := range integers {
		s += i
	}

	return s
}

// PowInt is integer version of math.Pow
// PowInt calculate a power by Binary Power (二分累乗法(O(log e))).
func PowInt(a, e int) int {
	if a < 0 || e < 0 {
		panic(errors.New("[argument error]: PowInt does not accept negative integers"))
	}

	if e == 0 {
		return 1
	}

	if e%2 == 0 {
		halfE := e / 2
		half := PowInt(a, halfE)
		return half * half
	}

	return a * PowInt(a, e-1)
}

// AbsInt is integer version of math.Abs
func AbsInt(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

// Gcd returns the Greatest Common Divisor of two natural numbers.
// Gcd only accepts two natural numbers (a, b >= 1).
// 0 or negative number causes panic.
// Gcd uses the Euclidean Algorithm.
func Gcd(a, b int) int {
	if a <= 0 || b <= 0 {
		panic(errors.New("[argument error]: Gcd only accepts two NATURAL numbers"))
	}
	if a < b {
		a, b = b, a
	}

	// Euclidean Algorithm
	for b > 0 {
		div := a % b
		a, b = b, div
	}

	return a
}

// Lcm returns the Least Common Multiple of two natural numbers.
// Lcd only accepts two natural numbers (a, b >= 1).
// 0 or negative number causes panic.
// Lcd uses the Euclidean Algorithm indirectly.
func Lcm(a, b int) int {
	if a <= 0 || b <= 0 {
		panic(errors.New("[argument error]: Gcd only accepts two NATURAL numbers"))
	}

	// a = a'*gcd, b = b'*gcd, a*b = a'*b'*gcd^2
	// a' and b' are relatively prime numbers
	// gcd consists of prime numbers, that are included in a and b
	gcd := Gcd(a, b)

	// not (a * b / gcd), because of reducing a probability of overflow
	return (a / gcd) * b
}

// Strtoi is a wrapper of strconv.Atoi().
// If strconv.Atoi() returns an error, Strtoi calls panic.
func Strtoi(s string) int {
	if i, err := strconv.Atoi(s); err != nil {
		panic(errors.New("[argument error]: Strtoi only accepts integer string"))
	} else {
		return i
	}
}

// PrintIntsLine returns integers string delimited by a space.
func PrintIntsLine(A ...int) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.Itoa(A[i])
		// str := strconv.FormatInt(A[i], 10)  // 64bit int version
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

/********** FAU standard libraries **********/

//fmt.Sprintf("%b\n", 255) 	// binary expression

/********** I/O usage **********/

//str := ReadString()
//i := ReadInt()
//X := ReadIntSlice(n)
//S := ReadRuneSlice()
//a := ReadFloat64()
//A := ReadFloat64Slice(n)

//str := ZeroPaddingRuneSlice(num, 32)
//str := PrintIntsLine(X...)

/*******************************************************************/

const MOD = 1000000000 + 7
const ALPHABET_NUM = 26
const INF_INT64 = math.MaxInt64
const INF_BIT60 = 1 << 60

func solve() {
	n := ReadInt()
	q := ReadIntSlice(n)
	p := make([]int, n)
	nums := make(map[int]int,n)
	for i:=0;i<n;i++{
		nums[i+1]=i+1
	}
	p[0]=q[0]
	delete(nums, q[0])
	for i := 1; i < n; i++ {
		qq := q[i]
		if qq > q[i-1] {
			p[i] = qq
			delete(nums, qq)
			continue
		}
		has :=  false
		for v := range nums {
			if v<qq {
				p[i] = v
				delete(nums, v)
				has= true
				break
			}
		}
		if !has {
			fmt.Println(-1)
			return
		}
	}
	fmt.Println(PrintIntsLine(p...))
}

func main() {
	t := ReadInt()
	//t :=1
	for ; t > 0; t-- {
		solve()
	}
}

package main

import (
	"fmt"
)

func solve() {
	var n int
	fmt.Scan(&n)
	q:= make([]int,n)
	for i:=0; i<n; i++{
		fmt.Scanf("%d", &q[i])
	}
	p := make([]int, n)
	nums := make(map[int]int,n)
	p[0]=q[0]
	nums[q[0]]++
	start:=0
	for i := 1; i < n; i++ {
		qq := q[i]
		if qq > q[i-1] {
			p[i] = qq
			nums[qq]++
			continue
		}
		has :=  false
		for k:=start+1; k<qq;k++ {
			if _, ok := nums[k]; !ok {
				p[i] = k
				nums[k]++
				has= true
				start=k
				break
			}
		}
		if !has {
			fmt.Println(-1)
			return
		}
	}
	for _,v:= range p{
		fmt.Printf("%d ",v)
	}
	fmt.Println()
}

func main() {
	var t int
	fmt.Scanf("%d\n",&t)
	//t :=1
	for ; t > 0; t-- {
		solve()
	}
}

package main

import (
	"bufio"
	"errors"
	"fmt"
	"io"
	"math"
	"os"
	"runtime"
	"strconv"
)

/*********** I/O ***********/

var (
	// ReadString returns a WORD string.
	ReadString func() string
	stdout     *bufio.Writer
)

func init() {
	var f *os.File
	if runtime.GOROOT() == "C:\\SOFT\\Go" {
		f, _ = os.Open("input.txt")
		//defer f.Close()
	} else {
		f = os.Stdin
	}
	ReadString = newReadString(f)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	// r.Buffer(make([]byte, 1024), int(1e+11)) // for AtCoder
	r.Buffer(make([]byte, 1024), int(1e+9)) // for Codeforces
	// Split sets the split function for the Scanner. The default split function is ScanLines.
	// Split panics if it is called after scanning has started.
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

// ReadInt returns an integer.
func ReadInt() int {
	return int(readInt64())
}
func ReadInt2() (int, int) {
	return int(readInt64()), int(readInt64())
}
func ReadInt3() (int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64())
}
func ReadInt4() (int, int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64()), int(readInt64())
}

// ReadInt64 returns as integer as int64.
func ReadInt64() int64 {
	return readInt64()
}
func ReadInt64_2() (int64, int64) {
	return readInt64(), readInt64()
}
func ReadInt64_3() (int64, int64, int64) {
	return readInt64(), readInt64(), readInt64()
}
func ReadInt64_4() (int64, int64, int64, int64) {
	return readInt64(), readInt64(), readInt64(), readInt64()
}

func readInt64() int64 {
	i, err := strconv.ParseInt(ReadString(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

// ReadIntSlice returns an integer slice that has n integers.
func ReadIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt()
	}
	return b
}

// ReadInt64Slice returns as int64 slice that has n integers.
func ReadInt64Slice(n int) []int64 {
	b := make([]int64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt64()
	}
	return b
}

// ReadFloat64 returns an float64.
func ReadFloat64() float64 {
	return float64(readFloat64())
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(ReadString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

// ReadFloatSlice returns an float64 slice that has n float64.
func ReadFloat64Slice(n int) []float64 {
	b := make([]float64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadFloat64()
	}
	return b
}

// ReadRuneSlice returns a rune slice.
func ReadRuneSlice() []rune {
	return []rune(ReadString())
}

/*********** Debugging ***********/

// ZeroPaddingRuneSlice returns binary expressions of integer n with zero padding.
// For debugging use.
func ZeroPaddingRuneSlice(n, digitsNum int) []rune {
	sn := fmt.Sprintf("%b", n)

	residualLength := digitsNum - len(sn)
	if residualLength <= 0 {
		return []rune(sn)
	}

	zeros := make([]rune, residualLength)
	for i := 0; i < len(zeros); i++ {
		zeros[i] = '0'
	}

	res := []rune{}
	res = append(res, zeros...)
	res = append(res, []rune(sn)...)

	return res
}

/*********** DP sub-functions ***********/

// ChMin accepts a pointer of integer and a target value.
// If target value is SMALLER than the first argument,
//	then the first argument will be updated by the second argument.
func ChMin(updatedValue *int, target int) bool {
	if *updatedValue > target {
		*updatedValue = target
		return true
	}
	return false
}

// ChMax accepts a pointer of integer and a target value.
// If target value is LARGER than the first argument,
//	then the first argument will be updated by the second argument.
func ChMax(updatedValue *int, target int) bool {
	if *updatedValue < target {
		*updatedValue = target
		return true
	}
	return false
}

// NthBit returns nth bit value of an argument.
// n starts from 0.
func NthBit(num, nth int) int {
	return num >> uint(nth) & 1
}

// OnBit returns the integer that has nth ON bit.
// If an argument has nth ON bit, OnBit returns the argument.
func OnBit(num, nth int) int {
	return num | (1 << uint(nth))
}

// OffBit returns the integer that has nth OFF bit.
// If an argument has nth OFF bit, OffBit returns the argument.
func OffBit(num, nth int) int {
	return num & ^(1 << uint(nth))
}

// PopCount returns the number of ON bit of an argument.
func PopCount(num int) int {
	res := 0

	for i := 0; i < 70; i++ {
		if ((num >> uint(i)) & 1) == 1 {
			res++
		}
	}

	return res
}

/*********** Arithmetic ***********/

// Max returns the max integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Max(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m < integer {
			m = integer
		}
	}
	return m
}

// Min returns the min integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Min(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m > integer {
			m = integer
		}
	}
	return m
}

// Sum returns multiple integers sum.
func Sum(integers ...int) int {
	s := 0

	for _, i := range integers {
		s += i
	}

	return s
}

// PowInt is integer version of math.Pow
// PowInt calculate a power by Binary Power (二分累乗法(O(log e))).
func PowInt(a, e int) int {
	if a < 0 || e < 0 {
		panic(errors.New("[argument error]: PowInt does not accept negative integers"))
	}

	if e == 0 {
		return 1
	}

	if e%2 == 0 {
		halfE := e / 2
		half := PowInt(a, halfE)
		return half * half
	}

	return a * PowInt(a, e-1)
}

// AbsInt is integer version of math.Abs
func AbsInt(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

// Gcd returns the Greatest Common Divisor of two natural numbers.
// Gcd only accepts two natural numbers (a, b >= 1).
// 0 or negative number causes panic.
// Gcd uses the Euclidean Algorithm.
func Gcd(a, b int) int {
	if a <= 0 || b <= 0 {
		panic(errors.New("[argument error]: Gcd only accepts two NATURAL numbers"))
	}
	if a < b {
		a, b = b, a
	}

	// Euclidean Algorithm
	for b > 0 {
		div := a % b
		a, b = b, div
	}

	return a
}

// Lcm returns the Least Common Multiple of two natural numbers.
// Lcd only accepts two natural numbers (a, b >= 1).
// 0 or negative number causes panic.
// Lcd uses the Euclidean Algorithm indirectly.
func Lcm(a, b int) int {
	if a <= 0 || b <= 0 {
		panic(errors.New("[argument error]: Gcd only accepts two NATURAL numbers"))
	}

	// a = a'*gcd, b = b'*gcd, a*b = a'*b'*gcd^2
	// a' and b' are relatively prime numbers
	// gcd consists of prime numbers, that are included in a and b
	gcd := Gcd(a, b)

	// not (a * b / gcd), because of reducing a probability of overflow
	return (a / gcd) * b
}

// Strtoi is a wrapper of strconv.Atoi().
// If strconv.Atoi() returns an error, Strtoi calls panic.
func Strtoi(s string) int {
	if i, err := strconv.Atoi(s); err != nil {
		panic(errors.New("[argument error]: Strtoi only accepts integer string"))
	} else {
		return i
	}
}

// PrintIntsLine returns integers string delimited by a space.
func PrintIntsLine(A ...int) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.Itoa(A[i])
		// str := strconv.FormatInt(A[i], 10)  // 64bit int version
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

/********** FAU standard libraries **********/

//fmt.Sprintf("%b\n", 255) 	// binary expression

/********** I/O usage **********/

//str := ReadString()
//i := ReadInt()
//X := ReadIntSlice(n)
//S := ReadRuneSlice()
//a := ReadFloat64()
//A := ReadFloat64Slice(n)

//str := ZeroPaddingRuneSlice(num, 32)
//str := PrintIntsLine(X...)

/*******************************************************************/

const MOD = 1000000000 + 7
const ALPHABET_NUM = 26
const INF_INT64 = math.MaxInt64
const INF_BIT60 = 1 << 60

func solve() {
	n := ReadInt()
	q := ReadIntSlice(n)
	res := true
	p := make([]int,n)
	m := make([]bool,int(1e5+1))
	FOR:
	for i:=0; i<n;i++{
		qq := q[i]
		for {
			if !m[qq]{
				m[qq] = true
				break
			}
			qq--
			if qq<=0 {
				res = false
				break FOR
			}
		}
		p[i] = qq
	}
	if !res {
		fmt.Println(-1)
	}else {
		fmt.Println(PrintIntsLine(p[0:n-1]...))
	}
}

func main() {
	t := ReadInt()
	//t :=1
	for ; t > 0; t-- {
		solve()
	}
}

package main

import (
	"fmt"
)

func solve() {
	var n int
	fmt.Scan(&n)
	q:= make([]int,n)
	for i:=0; i<n; i++{
		fmt.Scanf("%d", &q[i])
	}
	p := make([]int, n)
	nums := make(map[int]int,n)
	p[0]=q[0]
	nums[q[0]]++
	start:=0
	for i := 1; i < n; i++ {
		qq := q[i]
		if qq > q[i-1] {
			p[i] = qq
			nums[qq]++
			continue
		}
		has :=  false
		for k:=start+1; k<qq;k++ {
			if _, ok := nums[k]; !ok {
				p[i] = k
				nums[k]++
				has= true
				start=k
				break
			}
		}
		if !has {
			fmt.Println(-1)
			return
		}
	}
	fmt.Println(p)
}

func main() {
	var t int
	fmt.Scanf("%d\n",&t)
	//t :=1
	for ; t > 0; t-- {
		solve()
	}
}

package main

import (
	"bufio"
	"errors"
	"fmt"
	"io"
	"math"
	"os"
	"runtime"
	"strconv"
)

/*********** I/O ***********/

var (
	// ReadString returns a WORD string.
	ReadString func() string
	stdout     *bufio.Writer
)

func init() {
	var f *os.File
	if runtime.GOROOT() == "C:\\SOFT\\Go" {
		f, _ = os.Open("input.txt")
		//defer f.Close()
	} else {
		f = os.Stdin
	}
	ReadString = newReadString(f)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	// r.Buffer(make([]byte, 1024), int(1e+11)) // for AtCoder
	r.Buffer(make([]byte, 1024), int(1e+9)) // for Codeforces
	// Split sets the split function for the Scanner. The default split function is ScanLines.
	// Split panics if it is called after scanning has started.
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

// ReadInt returns an integer.
func ReadInt() int {
	return int(readInt64())
}
func ReadInt2() (int, int) {
	return int(readInt64()), int(readInt64())
}
func ReadInt3() (int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64())
}
func ReadInt4() (int, int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64()), int(readInt64())
}

// ReadInt64 returns as integer as int64.
func ReadInt64() int64 {
	return readInt64()
}
func ReadInt64_2() (int64, int64) {
	return readInt64(), readInt64()
}
func ReadInt64_3() (int64, int64, int64) {
	return readInt64(), readInt64(), readInt64()
}
func ReadInt64_4() (int64, int64, int64, int64) {
	return readInt64(), readInt64(), readInt64(), readInt64()
}

func readInt64() int64 {
	i, err := strconv.ParseInt(ReadString(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

// ReadIntSlice returns an integer slice that has n integers.
func ReadIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt()
	}
	return b
}

// ReadInt64Slice returns as int64 slice that has n integers.
func ReadInt64Slice(n int) []int64 {
	b := make([]int64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt64()
	}
	return b
}

// ReadFloat64 returns an float64.
func ReadFloat64() float64 {
	return float64(readFloat64())
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(ReadString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

// ReadFloatSlice returns an float64 slice that has n float64.
func ReadFloat64Slice(n int) []float64 {
	b := make([]float64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadFloat64()
	}
	return b
}

// ReadRuneSlice returns a rune slice.
func ReadRuneSlice() []rune {
	return []rune(ReadString())
}

/*********** Debugging ***********/

// ZeroPaddingRuneSlice returns binary expressions of integer n with zero padding.
// For debugging use.
func ZeroPaddingRuneSlice(n, digitsNum int) []rune {
	sn := fmt.Sprintf("%b", n)

	residualLength := digitsNum - len(sn)
	if residualLength <= 0 {
		return []rune(sn)
	}

	zeros := make([]rune, residualLength)
	for i := 0; i < len(zeros); i++ {
		zeros[i] = '0'
	}

	res := []rune{}
	res = append(res, zeros...)
	res = append(res, []rune(sn)...)

	return res
}

/*********** DP sub-functions ***********/

// ChMin accepts a pointer of integer and a target value.
// If target value is SMALLER than the first argument,
//	then the first argument will be updated by the second argument.
func ChMin(updatedValue *int, target int) bool {
	if *updatedValue > target {
		*updatedValue = target
		return true
	}
	return false
}

// ChMax accepts a pointer of integer and a target value.
// If target value is LARGER than the first argument,
//	then the first argument will be updated by the second argument.
func ChMax(updatedValue *int, target int) bool {
	if *updatedValue < target {
		*updatedValue = target
		return true
	}
	return false
}

// NthBit returns nth bit value of an argument.
// n starts from 0.
func NthBit(num, nth int) int {
	return num >> uint(nth) & 1
}

// OnBit returns the integer that has nth ON bit.
// If an argument has nth ON bit, OnBit returns the argument.
func OnBit(num, nth int) int {
	return num | (1 << uint(nth))
}

// OffBit returns the integer that has nth OFF bit.
// If an argument has nth OFF bit, OffBit returns the argument.
func OffBit(num, nth int) int {
	return num & ^(1 << uint(nth))
}

// PopCount returns the number of ON bit of an argument.
func PopCount(num int) int {
	res := 0

	for i := 0; i < 70; i++ {
		if ((num >> uint(i)) & 1) == 1 {
			res++
		}
	}

	return res
}

/*********** Arithmetic ***********/

// Max returns the max integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Max(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m < integer {
			m = integer
		}
	}
	return m
}

// Min returns the min integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Min(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m > integer {
			m = integer
		}
	}
	return m
}

// Sum returns multiple integers sum.
func Sum(integers ...int) int {
	s := 0

	for _, i := range integers {
		s += i
	}

	return s
}

// PowInt is integer version of math.Pow
// PowInt calculate a power by Binary Power (二分累乗法(O(log e))).
func PowInt(a, e int) int {
	if a < 0 || e < 0 {
		panic(errors.New("[argument error]: PowInt does not accept negative integers"))
	}

	if e == 0 {
		return 1
	}

	if e%2 == 0 {
		halfE := e / 2
		half := PowInt(a, halfE)
		return half * half
	}

	return a * PowInt(a, e-1)
}

// AbsInt is integer version of math.Abs
func AbsInt(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

// Gcd returns the Greatest Common Divisor of two natural numbers.
// Gcd only accepts two natural numbers (a, b >= 1).
// 0 or negative number causes panic.
// Gcd uses the Euclidean Algorithm.
func Gcd(a, b int) int {
	if a <= 0 || b <= 0 {
		panic(errors.New("[argument error]: Gcd only accepts two NATURAL numbers"))
	}
	if a < b {
		a, b = b, a
	}

	// Euclidean Algorithm
	for b > 0 {
		div := a % b
		a, b = b, div
	}

	return a
}

// Lcm returns the Least Common Multiple of two natural numbers.
// Lcd only accepts two natural numbers (a, b >= 1).
// 0 or negative number causes panic.
// Lcd uses the Euclidean Algorithm indirectly.
func Lcm(a, b int) int {
	if a <= 0 || b <= 0 {
		panic(errors.New("[argument error]: Gcd only accepts two NATURAL numbers"))
	}

	// a = a'*gcd, b = b'*gcd, a*b = a'*b'*gcd^2
	// a' and b' are relatively prime numbers
	// gcd consists of prime numbers, that are included in a and b
	gcd := Gcd(a, b)

	// not (a * b / gcd), because of reducing a probability of overflow
	return (a / gcd) * b
}

// Strtoi is a wrapper of strconv.Atoi().
// If strconv.Atoi() returns an error, Strtoi calls panic.
func Strtoi(s string) int {
	if i, err := strconv.Atoi(s); err != nil {
		panic(errors.New("[argument error]: Strtoi only accepts integer string"))
	} else {
		return i
	}
}

// PrintIntsLine returns integers string delimited by a space.
func PrintIntsLine(A ...int) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.Itoa(A[i])
		// str := strconv.FormatInt(A[i], 10)  // 64bit int version
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

/********** FAU standard libraries **********/

//fmt.Sprintf("%b\n", 255) 	// binary expression

/********** I/O usage **********/

//str := ReadString()
//i := ReadInt()
//X := ReadIntSlice(n)
//S := ReadRuneSlice()
//a := ReadFloat64()
//A := ReadFloat64Slice(n)

//str := ZeroPaddingRuneSlice(num, 32)
//str := PrintIntsLine(X...)

/*******************************************************************/

const MOD = 1000000000 + 7
const ALPHABET_NUM = 26
const INF_INT64 = math.MaxInt64
const INF_BIT60 = 1 << 60

func solve() {
	n := ReadInt()
	q := ReadIntSlice(n)
	p := make([]int, n)
	m := make([]bool, int(1e5+1))
	start := 0
	for i := 0; i < n; i++ {
		qq := start + 1
		for {
			if qq > q[i] {
				fmt.Println(-1)
				return
			}
			if !m[qq] {
				m[qq] = true
				break
			}
			qq++
		}
		p[i] = qq
		start = qq
	}
	fmt.Println(PrintIntsLine(p...))
}

func main() {
	t := ReadInt()
	//t :=1
	for ; t > 0; t-- {
		solve()
	}
}


package main

import (
	"bufio"
	"fmt"
	"os"
)

var reader *bufio.Reader = bufio.NewReader(os.Stdin)
var writer *bufio.Writer = bufio.NewWriter(os.Stdout)

func printf(f string, a ...interface{}) { fmt.Fprintf(writer, f, a...) }
func scanf(f string, a ...interface{})  { fmt.Fscanf(reader, f, a...) }

func main() {
	defer writer.Flush()
	var n, t1, t2 int
	scanf("%d\n", &n)
	arr := [111]int{}
	for i := 0; i < n; i++ {
		scanf("%d", &t1)
		arr[t1]++
	}

	p1, p2, dd, cnt := 0, 0, 1, 0

	mx := -1

	for mn := 1; mn < 100; mn++ {
		if arr[mn] == 0 {
			continue
		}
		for i := 100; i > mn; i-- {
			if arr[i] > 0 {
				for d := 2; d <= i; d++ {
					if i%d == 0 {
						lessn := i - i/d
						inc := (d - 1) * mn
						if inc < lessn {
							t1 = arr[mn]
							t2 = arr[i]
							if t2 > t1 {
								t2 = t1
							}
							if lessn-inc > mx {
								mx = lessn - inc
								p1 = mn
								p2 = i
								cnt = 1
								dd = d

							}
						}

					}
				}
			}

		}
	}
	arr[p1] -= cnt
	arr[p1*dd] += cnt
	arr[p2/dd] += cnt
	arr[p2] -= cnt

	ans := 0
	for i := 1; i < 111; i++ {
		ans += arr[i] * i
	}
	fmt.Println(ans)
}

package main

import (
	"fmt"
	"sort"
)

func main() {
	var n int
	fmt.Scan(&n)
	a := make([]int, n)
	for i := 0; i < n; i++ {
		fmt.Scan(&a[i])
	}
	sort.Ints(a)
	res := 0
	d := 0
	for i := 0; i < n; i++ {
		res += a[i]
		for j := 1; j <= a[i]; j++ {
			if a[i]%j == 0 {
				t := a[i] - a[i]/j + a[0] - a[0]*j
				if t > 0 && t > d {
					d = t
				}
			}
		}
	}
	fmt.Printf("%d", res-d)
}

package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	in := bufio.NewReader(os.Stdin)
	out := bufio.NewWriter(os.Stdout)
	defer out.Flush()
	n := 0
	fmt.Fscanf(in, "%d\n", &n)
	sum := 0
	a := make([]int, 101)
	q := 0
	for i := 1; i <= n; i++ {
		fmt.Fscanf(in, "%d", &q)
		a[q]++
		sum += q
	}
	fmt.Fscanf(in, "\n")
	max := 0
	//fmt.Println(a)
	for i := 100; i >= 1; i-- {
		for j := 1; j < i; j++ {
			if a[i] > 0 && a[j] > 0 {
				for k := 2; k <= i; k++ {
					if i%k == 0 {
						if (i+j)-(i/k+j*k) > max {
							max = (i + j) - (i/k + j*k)
							//fmt.Println(max, i, j, k)
						}
					}
				}
			}
		}
	}
	fmt.Fprintf(out, "%d\n", sum-max)
	return
}

package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
)

func main() {
	rd := bufio.NewReader(os.Stdin)
	var n int
	fmt.Fscanf(rd, "%d", &n)
	a := make([]int, n)
	for i := 0; i < n; i++ {
		fmt.Scan(&a[i])
	}
	sort.Ints(a)
	res := 0
	d := 0
	for i := 0; i < n; i++ {
		res += a[i]
		for j := 1; j <= a[i]; j++ {
			if a[i]%j == 0 {
				t := a[i] - a[i]/j + a[0] - a[0]*j
				if t > 0 && t > d {
					d = t
				}
			}
		}
	}
	fmt.Println(res - d)
}

package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
)

func main() {
	rd := bufio.NewReader(os.Stdin)
	var n int
	fmt.Fscanf(rd, "%d", &n)
	a := make([]int, n)
	for i := 0; i < n; i++ {
		fmt.Scan(&a[i])
	}
	sort.Ints(a)
	res := 0
	d := 0
	for i := 0; i < n; i++ {
		res += a[i]
		for j := 1; j <= a[i]; j++ {
			if a[i]%j == 0 {
				t := a[i] - a[i]/j + a[0] - a[0]*j
				if t > 0 && t > d {
					d = t
				}
			}
		}
	}
	fmt.Printf("%d", res-d)
}

package main

import (
	"bufio"
	"fmt"
	"os"
)

var reader *bufio.Reader = bufio.NewReader(os.Stdin)
var writer *bufio.Writer = bufio.NewWriter(os.Stdout)

func printf(f string, a ...interface{}) { fmt.Fprintf(writer, f, a...) }
func scanf(f string, a ...interface{})  { fmt.Fscanf(reader, f, a...) }

func main() {
	defer writer.Flush()
	var n, t1, t2 int
	scanf("%d\n", &n)
	arr := [111]int{}
	for i := 0; i < n; i++ {
		scanf("%d", &t1)
		arr[t1]++
	}
	flag := true
	for flag {
		flag = false
		mn := 111
		for i := 1; i < 101; i++ {
			if arr[i] > 0 {
				mn = i
				break
			}
		}

		for i := 100; i > mn; i-- {
			if flag {
				break
			}
			if arr[i] > 0 {
				for d := 2; d <= i; d++ {
					if i%d == 0 {

						lessn := i - i/d
						inc := (d - 1) * mn

						if inc < lessn {
							t1 = arr[mn]
							t2 = arr[i]
							if t2 > t1 {
								t2 = t1
							}
							arr[mn] -= t2
							arr[d*mn] += t2
							arr[i] -= t2
							arr[i/d] += t2
							flag = true
							break
						}

					}
				}
			}

		}
	}
	ans := 0
	for i := 1; i < 111; i++ {
		ans += arr[i] * i
	}
	fmt.Println(ans)
}

package main

import (
	"bufio"
	"fmt"
	"os"
)

var reader *bufio.Reader = bufio.NewReader(os.Stdin)
var writer *bufio.Writer = bufio.NewWriter(os.Stdout)

func printf(f string, a ...interface{}) { fmt.Fprintf(writer, f, a...) }
func scanf(f string, a ...interface{})  { fmt.Fscanf(reader, f, a...) }

func main() {
	defer writer.Flush()
	var n, t1, t2 int
	scanf("%d\n", &n)
	arr := [111]int{}
	for i := 0; i < n; i++ {
		scanf("%d", &t1)
		arr[t1]++
	}
	flag := true
	for flag {
		flag = false
		mn := 111
		for i := 1; i < 101; i++ {
			if arr[i] > 0 {
				mn = i
				break
			}
		}

		for i := 100; i > mn; i-- {
			if flag {
				break
			}
			if arr[i] > 0 {
				for d := i; d > 1; d-- {
					if i%d == 0 {

						lessn := i - i/d
						inc := (d - 1) * mn

						if inc < lessn {
							t1 = arr[mn]
							t2 = arr[i]
							if t2 > t1 {
								t2 = t1
							}
							arr[mn] -= t2
							arr[d*mn] += t2
							arr[i] -= t2
							arr[i/d] += t2
							flag = true
							break
						}

					}
				}
			}

		}
	}
	ans := 0
	for i := 1; i < 111; i++ {
		ans += arr[i] * i
	}
	fmt.Println(ans)
}

package main

import (
	"bufio"
	"fmt"
	"os"
)

var reader *bufio.Reader = bufio.NewReader(os.Stdin)
var writer *bufio.Writer = bufio.NewWriter(os.Stdout)

func printf(f string, a ...interface{}) { fmt.Fprintf(writer, f, a...) }
func scanf(f string, a ...interface{})  { fmt.Fscanf(reader, f, a...) }

func main() {
	defer writer.Flush()
	var n, t1, t2 int
	scanf("%d\n", &n)
	arr := [111]int{}
	for i := 0; i < n; i++ {
		scanf("%d", &t1)
		arr[t1]++
	}

	p1, p2, dd, cnt := 0, 0, 1, 0

	mx := -1

	for mn := 1; mn < 100; mn++ {
		if arr[mn] == 0 {
			continue
		}
		for i := 100; i > mn; i-- {
			if arr[i] > 0 {
				for d := 2; d <= i; d++ {
					if i%d == 0 {
						lessn := i - i/d
						inc := (d - 1) * mn
						if inc < lessn {
							t1 = arr[mn]
							t2 = arr[i]
							if t2 > t1 {
								t2 = t1
							}
							if t2*(lessn-inc) > mx {
								mx = t2 * (lessn - inc)
								p1 = mn
								p2 = i
								cnt = t2
								dd = d

							}
						}

					}
				}
			}

		}
	}
	arr[p1] -= cnt
	arr[p1*dd] += cnt
	arr[p2/dd] += cnt
	arr[p2] -= cnt

	ans := 0
	for i := 1; i < 111; i++ {
		ans += arr[i] * i
	}
	fmt.Println(ans)
}

package main

import (
	"bufio"
	"fmt"
	"os"
)

var reader *bufio.Reader = bufio.NewReader(os.Stdin)
var writer *bufio.Writer = bufio.NewWriter(os.Stdout)

func printf(f string, a ...interface{}) { fmt.Fprintf(writer, f, a...) }
func scanf(f string, a ...interface{})  { fmt.Fscanf(reader, f, a...) }

func main() {
	defer writer.Flush()
	var n, t1, t2 int
	scanf("%d\n", &n)
	arr := [111]int{}
	for i := 0; i < n; i++ {
		scanf("%d", &t1)
		arr[t1]++
	}

	p1, p2, dd, cnt := 0, 0, 1, 0

	mx := -1

	for mn := 1; mn < 100; mn++ {
		if arr[mn] == 0 {
			continue
		}
		for i := 100; i > mn; i-- {
			if arr[i] > 0 {
				for d := 2; d <= i; d++ {
					if i%d == 0 {
						lessn := i - i/d
						inc := (d - 1) * mn
						if inc < lessn {
							t1 = arr[mn]
							t2 = arr[i]
							if t2 > t1 {
								t2 = t1
							}
							if lessn-inc > mx {
								mx = lessn - inc
								p1 = mn
								p2 = i
								cnt = t2
								dd = d

							}
						}

					}
				}
			}

		}
	}
	arr[p1] -= cnt
	arr[p1*dd] += cnt
	arr[p2/dd] += cnt
	arr[p2] -= cnt

	ans := 0
	for i := 1; i < 111; i++ {
		ans += arr[i] * i
	}
	fmt.Println(ans)
}


package main

import (
	"bufio"
	"container/heap"
	. "fmt"
	"io"
	"os"
	"sort"
)

// github.com/EndlessCheng/codeforces-go
type hp struct{ sort.IntSlice }

func (h *hp) Push(v interface{}) { h.IntSlice = append(h.IntSlice, v.(int)) }
func (h *hp) Pop() interface{}   { a := h.IntSlice; v := a[len(a)-1]; h.IntSlice = a[:len(a)-1]; return v }
func (h *hp) push(v int)         { heap.Push(h, v) }
func (h *hp) pop() int           { return heap.Pop(h).(int) }
func (h hp) empty() bool         { return len(h.IntSlice) == 0 }
func (h hp) top() int            { return h.IntSlice[0] }

func run(_r io.Reader, _w io.Writer) {
	in := bufio.NewReader(_r)
	out := bufio.NewWriter(_w)
	defer out.Flush()

	var n, cntP int
	Fscan(in, &n)
	a := make([]int, n)
	for i := range a {
		Fscan(in, &a[i])
		if a[i] >= 0 {
			cntP++
		}
	}

	s := int64(0)
	h := hp{}
	for _, v := range a {
		if v >= 0 {
			s += int64(v)
		} else {
			if s+int64(v) >= 0 {
				h.push(v)
				s += int64(v)
			} else if !h.empty() {
				if v > h.top() {
					s -= int64(h.top())
					s += int64(v)
					h.IntSlice[0] = v
					heap.Fix(&h, 0)
				}
			}
		}
	}
	Fprintln(out, cntP+h.Len())
}

func main() { run(os.Stdin, os.Stdout) }

package main

import (
	"bufio"
	"bytes"
	"container/heap"
	"fmt"
	"os"
)

const (
	MOD int64 = 1e9+7
	NL byte = byte('\n')
	SP byte = byte(' ')
)

var (
	in *bufio.Scanner
	out *bufio.Writer

	n int
	a [200000]int
	res int
)

func main() {
	initBuffer()
	var t int = 1
	// t = getInt()
	for i := 0; i < t; i++ {
		solve()
	}
	// test()
	out.Flush()
}

func solve() {
	initialize()
	input()
	count()
	output()
}

func initialize() {

}

func input() {
	n = getInt()
	for i := 0; i < n; i++ {
		a[i] = getInt()
	}
}

type IntHeap []int
type any = interface{}

func (h IntHeap) Len() int           { return len(h) }
func (h IntHeap) Less(i, j int) bool { return h[i] < h[j] }
func (h IntHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *IntHeap) Push(x any) {
	// Push and Pop use pointer receivers because they modify the slice's length,
	// not just its contents.
	*h = append(*h, x.(int))
}

func (h *IntHeap) Pop() any {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}

func count() {
	var cur int64
	h := &IntHeap{}
	heap.Init(h)
	for i := 0; i < n; i++ {
		res++
		cur += int64(a[i])
		heap.Push(h, a[i])
		if cur < 0 {
			res--
			cur -= int64((*h)[0])
			heap.Pop(h)
		}
	}
}

func output() {
	out.Write(intToBytes(res))
}

func test() {
	fmt.Print()
}

func initBuffer() {
	in = bufio.NewScanner(os.Stdin)
	in.Buffer([]byte{}, 4 * 1024 * 1024)
	in.Split(scanWords)
	out = bufio.NewWriter(os.Stdout)
}

func scanWords(data []byte, atEOF bool) (advance int, token []byte, err error) {
	if atEOF && len(data) == 0 {
		return 0, nil, nil
	}
	i := bytes.IndexByte(data, '\n')
	j := bytes.IndexByte(data, ' ')
	ind := min(i, j)
	if ind < 0 {
		ind = max(i, j)
	}
	if ind >= 0 {
		return ind + 1, dropCR(data[0:ind]), nil
	}
	if atEOF {
		return len(data), dropCR(data), nil
	}
	return 0, nil, nil
}

func dropCR(data []byte) []byte {
	if len(data) > 0 && data[len(data)-1] == '\r' {
		return data[:len(data)-1]
	}
	return data
}

func getFloat() float64 {
	in.Scan()
	b := in.Bytes()
	var isNeg bool
	if b[0] == '-' {
		isNeg = true
		b = b[1:]
	}
	var res1 int64
	for i := 0; i < len(b); i++ {
		if b[i] == '.' {
			b = b[i+1:]
			break
		}
		res1 *= 10
		res1 += int64(b[i]) - 48
		if i == len(b) - 1 {
			b = b[:0]
		}
	}
	var res2 float64
	for i := len(b); i > 0; i-- {
		res2 += float64(b[i-1]) - 48
		res2 /= 10
	}
	if isNeg {
		res1 *= -1
		res2 *= -1
	}
	return float64(res1) + res2
}

func getInt() int {
	in.Scan()
	b := in.Bytes()
	var isNeg bool
	if b[0] == '-' {
		isNeg = true
		b = b[1:]
	}
	var res int
	for i := 0; i < len(b); i++ {
		res *= 10
		res += int(b[i]) - 48
	}
	if isNeg {
		res *= -1
	}
	return res
}

func getInt64() int64 {
	in.Scan()
	b := in.Bytes()
	var isNeg bool
	if b[0] == '-' {
		isNeg = true
		b = b[1:]
	}
	var res int64
	for i := 0; i < len(b); i++ {
		res *= 10
		res += int64(b[i]) - 48
	}
	if isNeg {
		res *= -1
	}
	return res
}

func getString() string {
	in.Scan()
	return in.Text()
}

func intToBytes(n int) []byte {
	var res [33]byte
	var isNeg bool
	if n < 0 {
		isNeg = true
		n = -n
	}
	var l int = 33
	for n > 0 {
		l--
		res[l] = byte(n % 10 + 48)
		n /= 10
	}
	if l == 33 {
		l--
		res[l] = byte(48)
	}
	if isNeg {
		l--
		res[l] = byte(45)
	}
	return res[l:]
}

func int64ToBytes(n int64) []byte {
	var res [65]byte
	var isNeg bool
	if n < 0 {
		isNeg = true
		n = -n
	}
	var l int = 65
	for n > 0 {
		l--
		res[l] = byte(n % 10 + 48)
		n /= 10
	}
	if l == 65 {
		l--
		res[l] = byte(48)
	}
	if isNeg {
		l--
		res[l] = byte(45)
	}
	return res[l:]
}

func bsLower(arr []int, n int) int {
	var minN, midN, maxN int
	maxN = len(arr)
	for maxN - 1 > minN {
		midN = (minN + maxN) / 2
		if arr[midN] < n {
			minN = midN
		} else {
			maxN = midN
		}
	}
	if arr[minN] >= n {
		return minN
	}
	return maxN
}

func bsLower64(arr []int64, n int64) int {
	var minN, midN, maxN int
	maxN = len(arr)
	for maxN - 1 > minN {
		midN = (minN + maxN) / 2
		if arr[midN] < n {
			minN = midN
		} else {
			maxN = midN
		}
	}
	if arr[minN] >= n {
		return minN
	}
	return maxN
}

func bsUpper(arr []int, n int) int {
	var minN, midN, maxN int
	maxN = len(arr)
	for maxN - 1 > minN {
		midN = (minN + maxN) / 2
		if arr[midN] <= n {
			minN = midN
		} else {
			maxN = midN
		}
	}
	if arr[minN] > n {
		return minN
	}
	return maxN
}

func bsUpper64(arr []int64, n int64) int {
	var minN, midN, maxN int
	maxN = len(arr)
	for maxN - 1 > minN {
		midN = (minN + maxN) / 2
		if arr[midN] <= n {
			minN = midN
		} else {
			maxN = midN
		}
	}
	if arr[minN] > n {
		return minN
	}
	return maxN
}

func max(n1, n2 int) int {
	if n1 > n2 {
		return n1
	}
	return n2
}

func max64(n1, n2 int64) int64 {
	if n1 > n2 {
		return n1
	}
	return n2
}

func min(n1, n2 int) int {
	if n1 < n2 {
		return n1
	}
	return n2
}

func min64(n1, n2 int64) int64 {
	if n1 < n2 {
		return n1
	}
	return n2
}

func yes(res, isUpperCase bool) bool {
	var arr [4]string = [4]string{"No", "Yes", "NO", "YES"}
	var ind int
	if res == true {
		ind = 1
	}
	if isUpperCase == true {
		ind += 2
	}
	out.WriteString(arr[ind])
	out.WriteByte(NL)
	return res
}

package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
)
type IntHeap []int

func (h IntHeap) Len() int           { return len(h) }
func (h IntHeap) Less(i, j int) bool { return h[i] < h[j] }
func (h IntHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *IntHeap) Push(x interface{}) {
	// Push and Pop use pointer receivers because they modify the slice's length,
	// not just its contents.
	*h = append(*h, x.(int))
}

func (h *IntHeap) Pop() interface{} {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}
func main() {
	var n int
	in := bufio.NewReader(os.Stdin)
	out := os.Stdout
	fmt.Fscan(in,&n)
	a := make([]int,n+5)
	for i:=1;i<=n;i++{
		fmt.Fscan(in,&a[i])
	}
	st := &IntHeap{}
	heap.Init(st)
	var cur int64
	cur = 0
	ret := 0
	for i:=1;i<=n;i++{
		if a[i]>=0{
			cur += int64(a[i])
			ret++
		}else{
			if cur + int64(a[i]) >= 0{
				cur = cur + int64(a[i])
				heap.Push(st,a[i])
				ret++
			}else{
				if len(*st)>0{
					if (*st)[0]<a[i]{
						cur -= int64((*st)[0])
						cur += int64(a[i])
						heap.Pop(st)
						heap.Push(st,a[i])
					}
				}
			}
		}
	}
	fmt.Fprintln(out,ret)
}

package main

import (
	"bufio"
	"container/heap"
	. "fmt"
	"io"
	"os"
	"sort"
)

// github.com/EndlessCheng/codeforces-go
type hp struct{ sort.IntSlice }

func (h *hp) Push(v interface{}) { h.IntSlice = append(h.IntSlice, v.(int)) }
func (h *hp) Pop() interface{}   { a := h.IntSlice; v := a[len(a)-1]; h.IntSlice = a[:len(a)-1]; return v }
func (h *hp) push(v int)         { heap.Push(h, v) }
func (h hp) empty() bool         { return len(h.IntSlice) == 0 }
func (h hp) top() int            { return h.IntSlice[0] }

func CF1526C2(_r io.Reader, out io.Writer) {
	in := bufio.NewReader(_r)
	var n, cntP int
	Fscan(in, &n)
	a := make([]int, n)
	for i := range a {
		Fscan(in, &a[i])
		if a[i] >= 0 {
			cntP++
		}
	}

	s := int64(0)
	h := hp{}
	for _, v := range a {
		if v >= 0 {
			s += int64(v)
		} else {
			if s+int64(v) >= 0 {
				h.push(v)
				s += int64(v)
			} else if h.Len() > 0 && v > h.top() {
				s -= int64(h.top())
				s += int64(v)
				h.IntSlice[0] = v
				heap.Fix(&h, 0)
			}
		}
	}
	Fprint(out, cntP+h.Len())
}

func main() { CF1526C2(os.Stdin, os.Stdout) }

package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"math"
	"os"
)

type Item struct {
	value    int
	priority int
	index    int
}

type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }

func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = j
	pq[j].index = i
}

func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}

func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	old[n-1] = nil
	item.index = -1
	*pq = old[:n-1]
	return item
}

func (pq *PriorityQueue) update(item *Item, value int, priority int) {
	item.value = value
	item.priority = priority
	heap.Fix(pq, item.index)
}

var in *bufio.Reader = bufio.NewReader(os.Stdin)
var out *bufio.Writer = bufio.NewWriter(os.Stdout)

func main() {
	defer out.Flush()
	solve := func(Case int) {
		var n int
		fmt.Fscan(in, &n)
		a := make([]int, n)
		for i := range a {
			fmt.Fscan(in, &a[i])
		}
		pq := PriorityQueue{}
		heap.Init(&pq)
		cur := int64(0)
		for i, elem := range a {
			heap.Push(&pq, &Item{elem, elem, i})
			cur += int64(elem)
			for cur < 0 {
				top := (*pq[0]).value
				cur -= int64(top)
				heap.Pop(&pq)
			}
		}
		fmt.Fprintln(out, len(pq))
	}

	T := 1
	//fmt.Fscan(in, &T) //
	for Case := 1; Case <= T; Case++ {
		solve(Case)
	}
}

func powMod(x, y, mod int64) int64 {
	ans := int64(1)
	for y != 0 {
		if y&1 != 0 {
			ans = (ans * x) % mod
		}
		y = y >> 1
		x = (x * x) % mod
	}
	return ans
}
func max(x ...int) int {
	ans := math.MinInt32
	for i := range x {
		if x[i] > ans {
			ans = x[i]
		}
	}
	return ans
}

func min(x ...int) int {
	ans := math.MaxInt32
	for i := range x {
		if x[i] < ans {
			ans = x[i]
		}
	}
	return ans
}
func gcd(x, y int) int {
	for y != 0 {
		x, y = y, x%y
	}
	return x
}

func reverse(s []byte) []byte {
	a := []byte(s)
	for i, j := 0, len(a)-1; i < j; i, j = i+1, j-1 {
		a[i], a[j] = a[j], a[i]
	}
	return a
}

package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
)

type viPair struct {
	v  int
	hi int // *viPair 在 mh 中的下标，可随着 Push Pop 等操作自动改变
}
type mh []*viPair // mh 指 modifiable heap

func (h mh) Len() int              { return len(h) }
func (h mh) Less(i, j int) bool    { return h[i].v > h[j].v } // > 为最大堆
func (h mh) Swap(i, j int)         { h[i], h[j] = h[j], h[i]; h[i].hi = i; h[j].hi = j }
func (h *mh) Push(v interface{})   { *h = append(*h, v.(*viPair)) }
func (h *mh) Pop() interface{}     { a := *h; v := a[len(a)-1]; *h = a[:len(a)-1]; return v }
func (h *mh) push(v int) *viPair   { p := &viPair{v, len(*h)}; heap.Push(h, p); return p }
func (h *mh) pop() *viPair         { return heap.Pop(h).(*viPair) }
func (h *mh) fix(i int)            { heap.Fix(h, i) }
func (h *mh) remove(i int) *viPair { return heap.Remove(h, i).(*viPair) }
func (h mh) top() int              { return h[0].v }

var rr = bufio.NewReader(os.Stdin)
var ww = bufio.NewWriter(os.Stdout)

var n int

func max(x, y int) int {
	if x >= y {
		return x
	} else {
		return y
	}
}

func main() {
	defer ww.Flush()
	fmt.Fscan(rr, &n)
	nums := make([]int, n)
	for i := 0; i < n; i++ {
		fmt.Fscan(rr, &nums[i])
	}
	sum, take, ans := 0, 0, 0
	hp := mh{}
	for i := 0; i < n; i++ {
		if nums[i] >= 0 {
			sum += nums[i]
			take++
		} else {
			sum += nums[i]
			take++
			hp.push(-nums[i])
			for hp.Len() > 0 && sum < 0 {
				sum += hp.top()
				take--
				hp.pop()
			}
		}
		ans = max(ans, take)
	}
	fmt.Fprintln(ww, ans)
}

package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func Readln(r *bufio.Reader) (string, error) {
	var (
		isPrefix bool  = true
		err      error = nil
		line, ln []byte
	)
	for isPrefix && err == nil {
		line, isPrefix, err = r.ReadLine()
		ln = append(ln, line...)
	}
	return string(ln), err
}

type PQItem struct {
	value    string // The value of the item; arbitrary.
	priority int    // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}

// A PriorityQueue implements heap.Interface and holds PQItems.
type PriorityQueue []*PQItem

func (pq PriorityQueue) Len() int { return len(pq) }

func (pq PriorityQueue) Less(i, j int) bool {
	// Min heap instead of the Max heap in the example
	return pq[i].priority < pq[j].priority
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = i
	pq[j].index = j
}

func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*PQItem)
	item.index = n
	*pq = append(*pq, item)
}

func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	old[n-1] = nil  // avoid memory leak
	item.index = -1 // for safety
	*pq = old[0 : n-1]
	return item
}

// update modifies the priority and value of an PQItem in the queue.
func (pq *PriorityQueue) update(item *PQItem, value string, priority int) {
	item.value = value
	item.priority = priority
	heap.Fix(pq, item.index)
}

func main() {
	reader := bufio.NewReader(os.Stdin)
	pk, _ := Readln(reader)
	k, _ := strconv.Atoi(pk)
	l2, _ := Readln(reader)
	pvals := strings.Split(l2, " ")
	vals := make([] int, k)
	for i:= range vals {
		vals[i],_ = strconv.Atoi(pvals[i])
	}
	pq := make(PriorityQueue , 0)
	heap.Init(&pq)
	hp := int64(0)
	for i,priority := range vals {
		temp := &PQItem{
			priority: priority,
			index: i,
		}
		hp+= int64(priority)
		//heap.Push(&pq,temp)
		if hp>= 0 {
			heap.Push(&pq,temp)
		} else {
			heap.Push(&pq,temp)
			hp-= int64(heap.Pop(&pq).(*PQItem).priority)
		}

	}
	//for i:= range pq {
	//	fmt.Println(pq[i].priority)
	//}
	fmt.Println(len(pq))
}

package main

import (
	"bufio"
	"bytes"
	"fmt"
	"os"
	"sort"
)

const (
	MOD int64 = 1e9+7
	NL byte = byte('\n')
	SP byte = byte(' ')
)

var (
	in *bufio.Scanner
	out *bufio.Writer

	n int
	a [200000]int
	res int
)

func main() {
	initBuffer()
	var t int = 1
	// t = getInt()
	for i := 0; i < t; i++ {
		solve()
	}
	// test()
	out.Flush()
}

func solve() {
	initialize()
	input()
	count()
	output()
}

func initialize() {

}

func input() {
	n = getInt()
	for i := 0; i < n; i++ {
		a[i] = getInt()
	}
}

func count() {
	sort.Ints(a[:n])
	var cur int64
	for i := n - 1; i >= 0; i-- {
		cur += int64(a[i])
		if cur < 0 {
			return
		}
		res++
	}
}

func output() {
	out.Write(intToBytes(res))
}

func test() {
	fmt.Print()
}

func initBuffer() {
	in = bufio.NewScanner(os.Stdin)
	in.Buffer([]byte{}, 4 * 1024 * 1024)
	in.Split(scanWords)
	out = bufio.NewWriter(os.Stdout)
}

func scanWords(data []byte, atEOF bool) (advance int, token []byte, err error) {
	if atEOF && len(data) == 0 {
		return 0, nil, nil
	}
	i := bytes.IndexByte(data, '\n')
	j := bytes.IndexByte(data, ' ')
	ind := min(i, j)
	if ind < 0 {
		ind = max(i, j)
	}
	if ind >= 0 {
		return ind + 1, dropCR(data[0:ind]), nil
	}
	if atEOF {
		return len(data), dropCR(data), nil
	}
	return 0, nil, nil
}

func dropCR(data []byte) []byte {
	if len(data) > 0 && data[len(data)-1] == '\r' {
		return data[:len(data)-1]
	}
	return data
}

func getFloat() float64 {
	in.Scan()
	b := in.Bytes()
	var isNeg bool
	if b[0] == '-' {
		isNeg = true
		b = b[1:]
	}
	var res1 int64
	for i := 0; i < len(b); i++ {
		if b[i] == '.' {
			b = b[i+1:]
			break
		}
		res1 *= 10
		res1 += int64(b[i]) - 48
		if i == len(b) - 1 {
			b = b[:0]
		}
	}
	var res2 float64
	for i := len(b); i > 0; i-- {
		res2 += float64(b[i-1]) - 48
		res2 /= 10
	}
	if isNeg {
		res1 *= -1
		res2 *= -1
	}
	return float64(res1) + res2
}

func getInt() int {
	in.Scan()
	b := in.Bytes()
	var isNeg bool
	if b[0] == '-' {
		isNeg = true
		b = b[1:]
	}
	var res int
	for i := 0; i < len(b); i++ {
		res *= 10
		res += int(b[i]) - 48
	}
	if isNeg {
		res *= -1
	}
	return res
}

func getInt64() int64 {
	in.Scan()
	b := in.Bytes()
	var isNeg bool
	if b[0] == '-' {
		isNeg = true
		b = b[1:]
	}
	var res int64
	for i := 0; i < len(b); i++ {
		res *= 10
		res += int64(b[i]) - 48
	}
	if isNeg {
		res *= -1
	}
	return res
}

func getString() string {
	in.Scan()
	return in.Text()
}

func intToBytes(n int) []byte {
	var res [33]byte
	var isNeg bool
	if n < 0 {
		isNeg = true
		n = -n
	}
	var l int = 33
	for n > 0 {
		l--
		res[l] = byte(n % 10 + 48)
		n /= 10
	}
	if l == 33 {
		l--
		res[l] = byte(48)
	}
	if isNeg {
		l--
		res[l] = byte(45)
	}
	return res[l:]
}

func int64ToBytes(n int64) []byte {
	var res [65]byte
	var isNeg bool
	if n < 0 {
		isNeg = true
		n = -n
	}
	var l int = 65
	for n > 0 {
		l--
		res[l] = byte(n % 10 + 48)
		n /= 10
	}
	if l == 65 {
		l--
		res[l] = byte(48)
	}
	if isNeg {
		l--
		res[l] = byte(45)
	}
	return res[l:]
}

func bsLower(arr []int, n int) int {
	var minN, midN, maxN int
	maxN = len(arr)
	for maxN - 1 > minN {
		midN = (minN + maxN) / 2
		if arr[midN] < n {
			minN = midN
		} else {
			maxN = midN
		}
	}
	if arr[minN] >= n {
		return minN
	}
	return maxN
}

func bsLower64(arr []int64, n int64) int {
	var minN, midN, maxN int
	maxN = len(arr)
	for maxN - 1 > minN {
		midN = (minN + maxN) / 2
		if arr[midN] < n {
			minN = midN
		} else {
			maxN = midN
		}
	}
	if arr[minN] >= n {
		return minN
	}
	return maxN
}

func bsUpper(arr []int, n int) int {
	var minN, midN, maxN int
	maxN = len(arr)
	for maxN - 1 > minN {
		midN = (minN + maxN) / 2
		if arr[midN] <= n {
			minN = midN
		} else {
			maxN = midN
		}
	}
	if arr[minN] > n {
		return minN
	}
	return maxN
}

func bsUpper64(arr []int64, n int64) int {
	var minN, midN, maxN int
	maxN = len(arr)
	for maxN - 1 > minN {
		midN = (minN + maxN) / 2
		if arr[midN] <= n {
			minN = midN
		} else {
			maxN = midN
		}
	}
	if arr[minN] > n {
		return minN
	}
	return maxN
}

func max(n1, n2 int) int {
	if n1 > n2 {
		return n1
	}
	return n2
}

func max64(n1, n2 int64) int64 {
	if n1 > n2 {
		return n1
	}
	return n2
}

func min(n1, n2 int) int {
	if n1 < n2 {
		return n1
	}
	return n2
}

func min64(n1, n2 int64) int64 {
	if n1 < n2 {
		return n1
	}
	return n2
}

func yes(res, isUpperCase bool) bool {
	var arr [4]string = [4]string{"No", "Yes", "NO", "YES"}
	var ind int
	if res == true {
		ind = 1
	}
	if isUpperCase == true {
		ind += 2
	}
	out.WriteString(arr[ind])
	out.WriteByte(NL)
	return res
}

package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
)
type IntHeap []int

func (h IntHeap) Len() int           { return len(h) }
func (h IntHeap) Less(i, j int) bool { return h[i] < h[j] }
func (h IntHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *IntHeap) Push(x interface{}) {
	// Push and Pop use pointer receivers because they modify the slice's length,
	// not just its contents.
	*h = append(*h, x.(int))
}

func (h *IntHeap) Pop() interface{} {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}
func main() {
	var n int
	in := bufio.NewReader(os.Stdin)
	out := os.Stdout
	fmt.Fscan(in,&n)
	a := make([]int,n+5)
	for i:=1;i<=n;i++{
		fmt.Fscan(in,&a[i])
	}
	st := &IntHeap{}
	heap.Init(st)
	cur := 0
	ret := 0
	for i:=1;i<=n;i++{
		if a[i]>=0{
			cur += a[i]
			ret++
		}else{
			if cur + a[i] >= 0{
				cur = cur + a[i]
				heap.Push(st,a[i])
				ret++
			}else{
				if len(*st)>0{
					if (*st)[0]<a[i]{
						cur -= (*st)[0]
						cur += a[i]
						heap.Pop(st)
						heap.Push(st,a[i])
					}
				}
			}
		}
	}
	fmt.Fprintln(out,ret)
}

package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"math"
	"os"
)

type Item struct {
	value    int
	priority int
	index    int
}

type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }

func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = j
	pq[j].index = i
}

func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}

func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	old[n-1] = nil
	item.index = -1
	*pq = old[:n-1]
	return item
}

func (pq *PriorityQueue) update(item *Item, value int, priority int) {
	item.value = value
	item.priority = priority
	heap.Fix(pq, item.index)
}

var in *bufio.Reader = bufio.NewReader(os.Stdin)
var out *bufio.Writer = bufio.NewWriter(os.Stdout)

func main() {
	defer out.Flush()
	solve := func(Case int) {
		var n int
		fmt.Fscan(in, &n)
		a := make([]int, n)
		for i := range a {
			fmt.Fscan(in, &a[i])
		}
		pq := PriorityQueue{}
		heap.Init(&pq)
		cur, ans := int64(0), int64(0)
		for i := range a {
			elem := a[i]
			if cur+int64(elem) >= 0 {
				ans++
				heap.Push(&pq, &Item{int(elem), int(elem), i})
				cur += int64(elem)
			} else {
				if len(pq) == 0 {
					continue
				}
				top := (*pq[0]).value
				if top < elem {
					heap.Pop(&pq)
					cur -= int64(top - elem)
				}
			}
		}
		fmt.Fprintln(out, ans)
	}

	T := 1
	//fmt.Fscan(in, &T) //
	for Case := 1; Case <= T; Case++ {
		solve(Case)
	}
}

func powMod(x, y, mod int64) int64 {
	ans := int64(1)
	for y != 0 {
		if y&1 != 0 {
			ans = (ans * x) % mod
		}
		y = y >> 1
		x = (x * x) % mod
	}
	return ans
}
func max(x ...int) int {
	ans := math.MinInt32
	for i := range x {
		if x[i] > ans {
			ans = x[i]
		}
	}
	return ans
}

func min(x ...int) int {
	ans := math.MaxInt32
	for i := range x {
		if x[i] < ans {
			ans = x[i]
		}
	}
	return ans
}
func gcd(x, y int) int {
	for y != 0 {
		x, y = y, x%y
	}
	return x
}

func reverse(s []byte) []byte {
	a := []byte(s)
	for i, j := 0, len(a)-1; i < j; i, j = i+1, j-1 {
		a[i], a[j] = a[j], a[i]
	}
	return a
}