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

Example input: I've read this book with much expectation, it was very boring all through out the book
Example output: Negative
Example explanation: Review writer does not like the book because it was boring, therefore it is a negative review.
Q: These are very good and not expensive.You buy these at Staples and they charge $5 more.I agree that a public exchange is needed. If anyone knows of one, can you please post that information here. We'll all appreciate it!Anybody want to trade the extras?
A:
Positive