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: Keepers of the dream... http://abcnews.go.com/Nightline/video/selma-stars-recreate-historic-1965-mlk-march-28339660  Responser: https://www.facebook.com/photo.php?fbid=10152555058737301&set=a.10151304738842301.1073741825.727407300&type=1
