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 useful, our family has 4 car keys, we always can't find it immediately. Since we use this product, we can find the keys quickly. Very convenient. The product has key rings, can't lose the keys anymore.
positive