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

Example Input: A really fun book, well worth your time if you like Pratchett. None of our old pals [Rincewind, Gaspode, Vimes, Susan] put in an appearence [other than the guy WHO TALKS LIKE THIS and an old monk with a broom, and they but briefly], but it does add some info to the overall Discworld mythology, and provides some laughs as well.
Example Output: Positive

Example Input: This product does not work with my ibook G4. As stated by some earlier reviews by other customers, the charger toggles between charging and not charging. Occasionally, if it is left on, it will continuously charge. I thought about keeping it, but it is unreliable and there are other third party options for $10 more.This one is going back to Amazon.
Example Output: Negative

Example Input: I really liked the part when John Candy was at the firing range. This movie is one of Candy's greatest.
Example Output:
Positive