Instructions: 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.
Input: I have older mats that have a ribbed surface and work great. These have small stiff points and actually hurt to lean on or kneel on. I can imagine that they hurt my cats paws ad that is why they tend to jump over them when exiting the littler box.
Output:
Negative