Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: A Must Have!

I would recommend this book to anyone who's getting ready to take the GK. I took the Math today (2/11/11) and I passed it easily. Everything that is on the test is in that book in actually, exactly the same order!! It's written in a language that is easy to understand and it's filled with tips and shortcuts. It's a great buy!