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: One day, James' sink sink became clogged. Sentence2: He tried using drain cleaner. Sentence3: He tried unclogging the drain with his hands. Sentence4: Nothing worked. Sentence5: James had to call a repairman.
Output:
James, Repairman