Given the task definition and input, reply with output. 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.

Very frustrated. Opened upon receiving so that it can expand. It's been 6 hours and still hard as a rock and curled up. Wondering how long it's going to take to expand to isn't normal shape.
negative