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

Ex Input:
Bought this for my 5 year old Justice Leaguer. My son is not a rough player but we went through 4 (YES, FOUR) of them before we finally got one where the elevator didn't break in the 1st 2 weeks. Mattel needs to get their act together and design toys that have durability. VERY disappointing!

Ex Output:
Negative

Ex Input:
Product reviews are very subjective. Based on the reviews of this boot I hoped for a great boot at a fair price. Instead I found the boot to be subpar in terms of comfort. They shoes were stiff and far too 'roomy'. My feet where floating inside them. I returned them immediately. I've had far more comfortable boots right out of the box.

Ex Output:
Negative

Ex Input:
...Mr. Jensen and his wife have developed a veritable cottage industry replete with workshops, seminars, presentations, publications, certifications -- if you've got the money then they have something to sell you...and all of it is centered around what is termed "brain-based learning"...but what this book presents is little more than 400 pages of scientifically unsubstantiated claims and recommendations...for example, it claims that the color yellow somehow enhances intellectual performance and, hence, classrooms should be painted yellow...however, he doesn't offer a shred of evidence to back that claim up...it's all just ridiculous...how does this stuff ever make it into print?

Ex Output:
Negative