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 loved hearing bedtime stories. Sentence2: One time he picked a scary book. Sentence3: Tim's dad was unsure about reading it. Sentence4: Tim insisted on it. Sentence5: He wound up getting scared.
Output:
Tim's dad, Tim