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

Ex Input:
Naader was my first yoga teacher. When we moved out of state, this video was my link to the best yoga routine I have ever done. I tried other instructors and other videos, but Naader's approach is the best -- a balanced mix of yoga instruction and inspiration. I have shared this tape with many friends (who then bought their own copy!) and they all agree that Naader's instructions are easy to follow and the pace is slow enough that beginners can figure out what is going on before the next pose; but not so slow that experienced students get bored. Furthermore, since he is doing the poses along with the student, he knows just when to offer that extra word of encouragement when you are about to give up! I find something new to ponder each time I listen to this tape. Naader's words are from the heart and they reach out to touch your heart as well as your body. Buy this tape and use it!!

Ex Output:
Positive


Ex 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!

Ex Output:
Negative


Ex Input:
It works but the next morning it has lost some shape and isn't as comfortable as it could be. For the price and the function is okay, the twin size made it right for our allowable space - but if you will need a longer term solution it is probably better to invest in a more expensive air bed.

Ex Output:

Negative