You will be given a definition of a task first, then some input of the task.
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: Tim has a history test. Sentence2: He has been studying for weeks. Sentence3: When he got to class he was still nervous. Sentence4: He saw his test and knew all the answers. Sentence5: Tim aced his test.
Output:
Tim