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

Ex Input:
I could not give this book a full 5 starts. For whatever reason, the book seemed to "bog-down" and I just wanted it to end. I will continue to read the series, but this one was not my favorite.

Ex Output:
Positive


Ex Input:
Although good quality product, it doesn't fit my ear at all. None of the sizes fit comfortably or snug. I can't use it at all and just wasted my money.

Ex Output:
Negative


Ex Input:
The book gives practical advice for those with diabetes. I've had type 2 diabetes for 13 years and when another ailment required me to use prednisone, I needed insulin. Dr. Bernstein's book taught me about the types of insulin and syringes. His book removed my apprehension about needles and possible low blood glucose. Like many pioneers in medicine, Dr. Bernstein's ideas were opposite to mainstream methods when his book was first introduced. However, his recommendation for a limited carbohydrate diet like that of the late Dr. Atkins, appears to be gaining acceptance. Control of diabetes is very much up to the patient. Dr. Bernstein's book puts life-saving knowledge in the hands of the patient. I have found it invaluable.

Ex Output:

Positive