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

[EX Q]: Book is a great read. Intriguing from start to finish. Cant find anything wrong to say. Would reccomend for beginer to advanced readers.
[EX A]: Positive

[EX Q]: Felt great until it dug into my waist while sitting causing damage to my surgical site. Now I'm in pain with and without it on.
[EX A]: Negative

[EX Q]: Piece of crap. All functions did not work when opened and stopped working during first use... horrible product. California Exotics should be ashamed of selling this junk. do not waste your money or shipping..
[EX A]:
Negative