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: Some kids set off fireworks on a mesa. Sentence2: The grass on the mesa burned. Sentence3: The fire came close to some houses. Sentence4: Firefighters put out the fire. Sentence5: Nobody was hurt.
Output:
Firefighters, Kids