Given reviews from Amazon, classify those review based on their content into two classes: Negative or Positive.

Ex Input:
I ordered 3 of these. They are sturdy, comfortable, and stay inflated. The electric motor in each easily and quickly inflates and (almost) deflates them. The height also makes them feel more like a real bed.However, if you want to completely deflate them for storage, that can be a real trick. I could never deflate any of them completely, so in frustration I cut one open to see what the problem is. A design flaw allows an internal plastic flap to cover the deflation port when they are almost empty. The more you try to vacuum or squeeze out air, the tighter the flap seals the port, sealing in the last bit of air.Now I know, and there's nothing I can do about it, but I feel better after attacking one with scissors...

Ex Output:
Negative

Ex Input:
My husband and I are expecting our first baby any day now. We opted to get a childbirth video versus attending a class. After doing some research and getting reccomendations from friends, I decided to purchase this video. While the information on the DVD is helpful and each segment is clear and easy to understand, the instructor presented it in such a way that made extremely painful to watch.The instructor continuously makes annoying jokes, mocks pregnant women and their partners, using the most unfunny and unflattering impersonations imaginable. Watching this woman's attempt stand-up routine was so uncomfortable that we often found ourselves fast forwarding through a lot of it. Please believe that neither me or my husband laughed during this DVD. Not once.I wish we had just gone to childbirth class.

Ex Output:
Negative

Ex Input:
It is a catechism ... what more to say? It does the job, presents the facts and gives a lot of information in concise form that can be used for further study. What it is not is a prayer book, philosophical discussion or flowery inspirational work. It is a catechism.

Ex Output:
Positive