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: Read my Hartford Courant op-ed on rail safetyfor far too long, our rail funding plan has been to simply patch and pray: http://j.mp/1Q8up6v  Responser: AL-sharq Al-awsat newspaper interview with Mahmud al-Hasani al-Sarkhi https://www.youtube.com/watch?v=jo2OBqDPwvo
