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

Example Input: I've been a longtime fan of Mercedes and own most of her Valdemar series. So, of course, I picked this book up at my local store. After wrestling through 50 pages, I gave up! I plan to sell it back to my local store ASAP- this is nothing better than a paperweight in my bookshelves. The worst part is, my boyfriend picked it up and tried reading it. Now he thinks that this is a good example of her work!
Example Output: Negative

Example Input: A thrilling story of get rich quick without scruples. It introduces the reader to excellent characterizations of the individuals involved. There is excitement through unusual circumstances including an extremely imaginative ending.
Example Output: Positive

Example Input: Great Door knocker. It has a very clean look to it and the peep hole isn't obvious. It's a little on the thin side but I guess you don't need much. It was easy to get engraved. It wasn't the easiest to install. Would have liked a template to assist with lining up the screws. Other than that, it looks very professional.
Example Output:
Positive