Instruct: Classify a given review as either positive or negative.
Query: Not a book for beginners

I first got hooked on Kakuro from an inexpensive paperback so I decided to upgrade to a higher quality book. I found that all the puzzles in this book are difficult, even the ones designated as "easy". For someone with experience solving difficult Kakuro puzzles, this book is challanging. However, if you are a beginner, you will become frustrated trying to solve the first puzzle and might not ever want to try another.