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

Let me give you an example: I've read this book with much expectation, it was very boring all through out the book
The answer to this example can be: Negative
Here is why: Review writer does not like the book because it was boring, therefore it is a negative review.

OK. solve this:
I have had several of these monitors. I use a two-monitor set-up.-The backlight on the first burned out one month out of warrantee. ViewSonic would not replace the first monitor- fair enough as it was out of warrantee. I purchased a replacement. When it came, the screen was blue, and the color could not be adjusted. ViewSonic sent a replacement which had a green screen, and again, the color could not be adjusted. They were unable to find another VA912b, so they sent a different model to replace it.-Meanwhile, my second monitor, again a VA912b burned out the backlight after less than six months of use.-Beware that the glowing reviews you see for this monitor may not take into account its poor reliability. Should you choose this monitor, be sure to get an extended warrantee! Better yet, do yourself a favor and choose another model or manufacturer.
Answer:
Negative