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: Yes, this isn't the best space heater I have ever owned, but it has a unique shape where it doesn't gather a bunch of dust, like past heaters have, and you can't beat the price for its performance.
Solution:
Positive