Q: In this task, you're given a story (which contains five sentences only). Your task is to find all the characters which are available in the given story.
Sentence1: Gary was about to play a very important chess game. Sentence2: He was scared that his opponent would beat him. Sentence3: He snuck into his opponent's hotel room and changed his medicine. Sentence4: The opponent got sick and could not play. Sentence5: Gary won the match by default.
A:
Opponent, Gary