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.

These CO detectors are mandatory in many states now. I happen that the man who cleans my carpets is the Captain of the town fire dept (also up for promotion to chief), and he always points out my fire hazards or things I do or don't really need to do. I had my first CO detector up on the ceiling next to my smoke detector. He told me it di not need to be on the ceiling, and it's easier to get a plug in one so you don't have to worry about the battery aspect. Then incidentally my ceiling one broke somehow. So I bought this one, plugged it in, in the hallway near my bedroom......he said to do that so you can hear it quickly, and loudly. It's doing it's thing. A little pricey, but actually one of the cheaper ones. He approved!
Positive