Given reviews from Amazon, classify those review based on their content into two classes: Negative or Positive.
One example: I've read this book with much expectation, it was very boring all through out the book
Solution is here: Negative
Explanation: Review writer does not like the book because it was boring, therefore it is a negative review.

Now, solve this: This toy was a pain to put together, and even worse to stay together. The elevator won't work, and I had to forcefully put some of the pieces together. Most people who reviewed this toy, had the same complaints, but I bought it anyway, because my nephew really wanted it. I'm glad that I only paid $15.00 for it, because it's not worth any more than that. Some pieces came off, before my nephew even got a chance to play with it.
Solution:
Negative