Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Best book on the subject

This book is simply the best. I enjoyed every page of it, and found myself mesmerized by all the information contained in the book. I was hesitate on buying the book because of the price, but was pleased to say that after reading the book very quickly just one time, I went to a yard sale and picked up two books for 50 cents each, and they are worth more than 50 dollars for each one. You can't go wrong in getting this book. Trust me.