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: John hated spinach as a child. Sentence2: John's daughter refused to eat spinach. Sentence3: John ate spinach in front of his daughter. Sentence4: His daughter ate it after he did. Sentence5: John eats spinach for his daughter's sake.
Example Output: John, John's daughter

Example Input: Sentence1: Dan wanted to get some exercise in today. Sentence2: Dan decided he would go to the local pool and swim several laps. Sentence3: However, when Dan arrived he noticed the facility was closed. Sentence4: Dan decided he would go back home and exercise there. Sentence5: Dan was disappointed that he could not swim in the pool.
Example Output: Dan

Example Input: Sentence1: Fanny's boat had gotten stuck in a bog. Sentence2: She grabbed her backpack and hopped over board. Sentence3: She pushed her way through one hundred and fifty yards of mud. Sentence4: She was exhausted when she reached the shore but grateful. Sentence5: When she undressed later she saw she was covered in leeches.
Example Output:
Leeches, Fanny