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

Example Input: This was my first purchase of a vibrator and was very disappointed. It was shipped very discreetly from Amazon directly, but it didn't work. I put in fresh batteries and it wouldn't turn on. I even tested the batteries, they were good, but this rabbit wasn't. Unfortunately, Amazon doesn't take returns on this type of personal product. I simple won't buy anything made by California Exotics again. I'll try one of the other brands next time.
Example Output: Negative

Example Input: I ordered this DVD & several others as presents. They all arrived in good shape & on time for Christmas morning.
Example Output: Positive

Example Input: Hogan is a member of that group of sci-fi writers who present bold ideas but don't particularly write well or develop characters (Isaac Asimov is the first, and best, member of that school of Sci-Fi writers.) His idea seems rather weak to me as ignores human (mainly male) nature. We have had thousands of years of war, sexism and the exclusion of various "outsider" groups (based on caste, race, tribe, income, etc.) Even studies of chimpanzees, humans closest relatives, have shown certain "outsider" males are physically abused by the "alpha males" of the group. Look at the primary source texts and warlike art of civilizations from the Aztec to the Sumerians and you will see intolerance is a problem of the y-chromosome, not social conditioning from one particular society. Matriarchy might be the only real answer to the world's problems.
Example Output:
Negative