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: Happy 240th birthday to the U.S. Army! Thank you to all who have served to keep us safe!  Responser: HAPPY BIRTHDAY! THANK YOU ALL FOR YOUR SERVICE!!!
