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: The Denver Broncos starting quarterback was injured. Sentence2: Brock was their backup quarterback. Sentence3: He took practice repetitions all week. Sentence4: Brock was ready to start their next game. Sentence5: He had a spectacular performance.
Output:
Brock, Denver broncos, Quarterback