Definition: Given a 'poster' sentence and a corresponding 'response' (often, from Facebook or Reddit)classify the sentiment of the given response into four categories: 1) Positive, 2) Negative, 3) Neutral, and 4) Mixed if it contains both positive and negative.
Input: Poster: BELLINGHAM, WA! I'll be at Village Books tonight at 7:00 for a Q&A and signing.  Responser: The burning world will be here tomorrow! I've been dying to get my hands on this book for years.
