Given the task definition and input, reply with output. 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.

Sentence1: Joan had to do a science project for school. Sentence2: She decided to study the effects of the sun on an egg on the sidewalk. Sentence3: She waited outside all day. Sentence4: By the end of the day, the egg was cooked, but inedible. Sentence5: Joan concluded that cooking eggs on the sidewalk is ill-advised.
Joan