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: This is one of the best video concerts ever. The sound, visuals and performances are top notch. It is a real joy. I have owned it a week and watched it 3 times already. Every performance is good. There are no dead spots during this concert and you get quite a number of them. A keeper. Memorable.
A:
Positive