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

Ex Input:
The subject is trivial and boring. The writing skill mediocre.I was stuck in Sri Lanka and downloaded it by mistake when learning how to use my new kindle. Decided to take a look.Sorry, perhaps just not my type of book. It is no literature.

Ex Output:
Negative

Ex Input:
As a student of jiujitsu i understood alot of the moves but i found that without previous knowledge these pictures and instructions were difficult to understand. I feel there is alot of good information but not worth buying.

Ex Output:
Negative

Ex Input:
I'd agreed with my fellow reviewer on "Retox" (CD #1), but "Detox" makes up for it -- it's a totally different sound.

Ex Output:
Positive