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: My dog was bored. Sentence2: I was working all day so I couldn't spend time with him. Sentence3: When I finished work I decided to play with my dog. Sentence4: He was so happy to finally have some fun! Sentence5: Alas, he fell sick and died.
Example output: I (myself), Dog
Example explanation: There is only two characters in given story, i.e., I (myself) and dog.
Q: Sentence1: Peter didn't like children and yet he was a clown. Sentence2: Every time he had to perform for children he would get a rash. Sentence3: He went to the doctor and he was told to stop being a clown. Sentence4: But as he didn't know how to do anything else he continued. Sentence5: Unfortunately his condition got worse and he had to stop for good.
A:
Peter, Children, Doctor