Given reviews from Amazon, classify those review based on their content into two classes: Negative or Positive.

Let me give you an example: I've read this book with much expectation, it was very boring all through out the book
The answer to this example can be: Negative
Here is why: Review writer does not like the book because it was boring, therefore it is a negative review.

OK. solve this:
Unlike the first Foundation book, which was a series of related but not inter-connected stories, Foundation and Empire has two longer stories. This lets Asimov flesh out the stories more, adding detail and plot intricacies. The first story, The Big and The Little, is not one of the series' strongest. However, the second story, The Mule, is the masterpiece of the series. It tells of a muntant, The Mule, who falls outside the scope of Hari Seldon's psychohistory as one supremely powerful individual. The story is told in almost detective story fashion similar to the first two Robot novels. It's quite as suspenseful and involving as Asimov at his best and one of his utmost classics. There's quite a lot of plot tangling and twists, and the ending is a shocker. It's not quite a cliffhanger but will definitely make you want to read the next book, which is great also. The whole series comes highly recommended.
Answer:
Positive