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 unit is well built and works really well. It was just used to startup from a drained battery(left my Mac on battery all nite..duh). Well, at 0% charged, I plugged this unit in and starting web browsing, in minutes the charge was at 2% and rising, as well as keeping up with the browsing demands. For the price, it cannot be beat. It also seems I keep forgetting to unplug the original charger when I pack to do travelling, so this new unit makes a great spare to keep packed in my laptop case.
Solution:
Positive