Given the task definition and input, reply with output. 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: Terrell was a terrible bowler. Sentence2: He decided to bowl more often to get better. Sentence3: He went to the bowling alley 4 times a week during the summer. Sentence4: His average improved from a 61 to a 73. Sentence5: Now Terrell was not as terrible as he was when he started.
Terrell