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: Yesterday, I joined the Bipartisan Task Force to Combat the Heroin Epidemic in a hearing on synthetic opioids. In 2015, there were 228 overdose deaths in Delaware. We need to come together across party lines to find a solution to this growing problem.  Responser: Thank you for working on this critical issue.
