Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Unputdownable!

Read this in a less than a day! Great story with Alex Cross, one of fiction's most likeable characters. Some people knock Patterson, but millions more love his stories. For me their accessibility to all is one of the great appeals, like with Steinbeck. Most chapters have amazing cliffhangers, so it was a case of "I'll read just one more chapter" a hundred times! A thrilling unputdownable read.