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: For those in DC for the #MarchForLife today, please join me for a reception in Room 2322 of the Rayburn House Office Building from 1:30 to 5 p.m.  Responser: Is that real or an Onion article?
