Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A complete waste

As a long time karate-ka (more than 50 years), I can assure you that this book is utter bilge. It is not worth wasting your time and small amount of money. The "author," is a complete fake with no knowledge of karate at all. Please don't give the con-artist your money. I would give it a zero rating if I could.