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: I bought this because it was a cheaper alternative to Mac's (ridiculously priced)$80 charger. At first it worked pretty good, but about a week or two after i got it it seems to not be working like it should. i think there is some kind of warranty, so i should try and exchange it...but sometimes when it is plugged into my computer it will charge for one second, then stop for one second, charge for one second, stop for one second, etc. It still manages to charge the computer, but im not sure if all this on\off stuff is necessarily good for my computer...
Solution:
Negative