Given reviews from Amazon, classify those review based on their content into two classes: Negative or Positive.
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Question: I bought this air mattress to use while my new bed was being shipped from back east, the bed lost air every night and I woke up almost on the floor. I tried to send it back but it was impossible to get back into the box.

Answer: Negative


Question: I have a small business and it was important that the envelope feeder work well. From day 1, this has been a nightmare. Components of the printer block the envelopes/labels and they don't feed properly. If you use internet postage, you lose money with the misfed labels/envelopes. I'm very disappointed and am shopping for a new printer now, only a short time after purchasing this one.

Answer: Negative


Question: This book is not for everyone. It is extremely scary and disturbing. At the same time, it is a fascinating look at the police work and prosecution that brought the murderous Manson Family to justice. The book is hard to put down; the in depth discussion on presenting a criminal case in court and developing evidence to support the case is outstanding. The main complaint is that the book is a few hundred pages too long. The author seems a little too self-promoting, but then again he did get a prosecution on one of the biggest murders in history.

Answer:
Positive