Instructions: 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.
Input: Sentence1: Bill and Joe were playing a video game. Sentence2: Bill beat Joe at the game. Sentence3: Joe was upset and being a poor sport. Sentence4: Joe threw down the controller. Sentence5: Bill quit playing games with Joe.
Output:
Bill, Joe