Given the task definition, example input & output, solve the new input case.
Given reviews from Amazon, classify those review based on their content into two classes: Negative or Positive.
Example: I've read this book with much expectation, it was very boring all through out the book
Output: Negative
Review writer does not like the book because it was boring, therefore it is a negative review.

New input case for you: This book is very detailed, technical and complex. If you're seriously considering exploring the photogravure technique on copper, this book is a must. It tells you everything you will ever need and all the complicated steps in the process. However, there are few historical or contemporary photogravure reproductions which is why this book gets only a four star rating from this reviewer. If you are seriously considering the photogravure process as one you would like to explore, I recommend starting with solar plates rather than copper. It is much less complicated and toxic. A very good resource is "Printmaking in the Sun" (2001) by Dan Welden, inventor of this method.
Output:
Positive