Given the task definition, example input & output, solve the new input case.
Given reviews from Amazon, classify those review based on their content into two classes: Negative or Positive.
Example: I've read this book with much expectation, it was very boring all through out the book
Output: Negative
Review writer does not like the book because it was boring, therefore it is a negative review.

New input case for you: A friend suggested this herb to me to help with my awful PMS. After taking Vitex for only three days during PMS, I began to feel horrible: very irritable, nauseous and foggy. After doing some research, I found that a percentage of women react very negatively to this herb -- some people remarked that they initially felt better, but then progressively felt worse and thought they were going crazy; some said they immediately felt terrible. I guess it's a gamble that many of us are willing to take to feel better though. Wish it had worked!
Output:
Negative