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: As a mother, grandmother, and former preschool teacher -- today's tragedy in Newtown weighs heavily on my heart. My thoughts go out to all those affected by it.  Responser: Please do something about gun control and mental health.
