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.

Example Input: Sentence1: Muriel and her sister always took the shortcut home. Sentence2: One day they decided to take the long way home. Sentence3: A strange man followed them and they got scared. Sentence4: They started running and screaming until they made it home. Sentence5: They told their parents and now they pick them up.
Example Output: Strange man, Muriel's parents, Muriel's sister, Muriel

Example Input: Sentence1: Will was moved up a grade because he was so smart. Sentence2: The teachers warned his dad that he wouldn't grow emotionally. Sentence3: His dad insisted on moving him up a grade. Sentence4: Will was hated throughout school. Sentence5: He is now a very confused and disliked adult.
Example Output: Will, Dad, School, Teachers

Example Input: Sentence1: Edward was lonely and wanted a girlfriend so he started dating. Sentence2: He went on a date with a girl named Joy. Sentence3: Edward liked her but she didn't like him so he got angry at her. Sentence4: Joy told Edward he had an anger problem and needed help. Sentence5: Edward discovered his anger prevented him from finding love.
Example Output:
Joy, Edward