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: I am working with Congresswoman Anna Eshoo to ensure the GOP doesn't cut critical Caltrain funding. We must stand together. Silicon Valley deserves the infrastructure it needs to thrive.  Responser: Great. They keep building more and more condos, and traffic keeps getting worse. We need Public Transit more than ever!
