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: Grassley to FCC on LightSquared: What are you hiding?  Responser: Will just one millionaire Senator stand up and say "I'm not taking a penny in pay until this matter is resolved and the budget is balanced"
