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: Bob was a bodybuilder. Sentence2: He used steroids. Sentence3: He decided to sell some at his gym. Sentence4: He was caught by the gym owner. Sentence5: He was promptly kicked out of the gym for life.
Output:
Gym owner, Bob