Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Could NOT put down!

I can not say enough about this book! I made the mistake of starting to read it at 4 in the morning. It was so great that I didn't even notice that the sun had come up and the birds were chirping. Luckily... I didn't have to go to work that day because I never got to sleep until 9 a.m. after I read the whole thing in one sitting. This is very rare for me as I usually get bored after 20 minutes of reading. Watching the relationship between Alex and Jo grow into such passion was a thrill and a great escape from reality.