Given the task definition and input, reply with output. Given reviews from Amazon, classify those review based on their content into two classes: Negative or Positive.

I have a VERY picky 4 month old who refuses to eat using any kind of nipple other than these. These are what they started him on in the hospital and although they are supposed to be disposable, we have been able to use nothing else since (despite numerous purchases of other brands to try with him.)
Positive