Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: The worst book written for students

This is one of the worst book written for students I have ever seen. With extremely hard to understand, insufficient explanations, I am wondering whom would be the target readers, professors or students? Unfortunately, a lot of schools were misguided to use this book simply because of the reputation of the schools where the authors work for, not the content of the book!