In this task, You are given a review of Amazon's food products. Your task is to divide them into two classes: negative or positive, depending on the content of the review.

Example Input: I have a smallish black dog that disappears into shadows and night an this collar is perfect to help keep an eye on him. He is so small I was able to get two equal lengths out of the collar portion and I love that it is rechargeable.
Example Output: positive

Example Input: If you already have the DeWalt batteries his is a great addition. This fan is so convenient to use that I end up using it all the time. It moves an impressive amount of air while at the same time is quiet. A 6Ah battery runs for over 10 hours on high.
Example Output: positive

Example Input: Doesn’t work. I wanted a more natural alternative but after several uses (following the directions) my drain still drains slowly. Haven't noticed any improvement.
Example Output:
negative