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

Ex Input:
When I purchased this product, I thought I was getting a good deal because of the cheaper price. However, once I received it, I knew I had made a mistake. I've been using this product for several years now, and I knew just by looking at this one that it wasn't right. The texture was incredibly thin, and the color was much lighter -- something that could only leave me to believe that maybe water had been added to it.Lesson learned -- spend the extra money -- you're paying for quality!

Ex Output:
Negative

Ex Input:
I found this movie pathetic at times. The drug use and plot line was, at times, absurd. I wish I hadn't wasted my $ renting this b/c it just wasn't worth it. The director's failed attempts at being "artsy" with the alligator, iguanas and the like was obvious and remedial and any action to be David LynchY was lost on practically anyone except perhaps the director.As you may surmise, this won't be one in my permanent library.

Ex Output:
Negative

Ex Input:
Gifford is one of the top experts on Heinlein's works, and his "A Reader's Companion" is an exhaustively researched and well-thought-out compendium of nearly all of Heinlein's work.I say "nearly" only because the book misses a few Heinlein collections and such that have been published in the few years since Gifford's 2000 printing. [...]I've been collecting Heinlein works for years, even very obscure ones, and I still learned of new things from Gifford's book.

Ex Output:
Positive