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: Carl was having a lot of trouble with his neighbor, a cranky old man. Sentence2: Whenever Carl left his house, the old man complained about something. Sentence3: After fighting with the old man, Carl always felt guilty for yelling. Sentence4: He decided no matter what, he wouldn't get mad, he'd just accept it. Sentence5: The man still complained, but Carl didn't let it bug him any more.
Output:
Neighbor, Carl