Instructions: 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.
Input: Sentence1: Harry left his house for work. Sentence2: Harry did not realize that someone was stalking the place. Sentence3: The person robbed Harry's house. Sentence4: Harry went home. Sentence5: Harry saw that he had been robbed and had contacted the police.
Output:
Police, Harry, Harry