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

Ex Input:
At 80" iong, this is an extra long twin, not a standard twin. Consequently I had to take back the sheets I bought, as they were 5" too short. I would have ordered a different model had I known that 80" wasn't standard. It's easier just to replace the sheets and I don't have time to send the bed back.

Ex Output:
Negative

Ex Input:
This is being written mostly in protest of the re-print. The stories in these series were always a little dull. But the art, the art was fantastic, and now they've taken it away. I dont have my old copies any more and now the old books are going for outrageous sums. I wanted to get these books for my kids someday--not any more.

Ex Output:
Negative

Ex Input:
This book is useful for teaching lower division undergraduate students the principles of microeconomics.It can be used as a supplementary book.Hazlitt emphasizes the important concept of opportunity cost,but neglects to incorporate any discussion of spillover effects and externalities(positive and negative,depletable and undepletable),market failure,public goods,the theory of second best,adverse selection,moral hazard, the principal-agent problem,etc.It is interesting that all these missing topics were originally covered by Adam Smith in The Wealth of Nations(1776),especially in Part V.

Ex Output:
Positive