Definition: 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: One day a woman was walking down the street. Sentence2: A man ran up behind her and stole her purse. Sentence3: The woman yelled for the police. Sentence4: A police officer heard and ran after the thief. Sentence5: The office apprehended the thief and returned the woman's purse.
Output:
A woman, A man, The police