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: John got up in the morning, all ready for his first class. Sentence2: Before he left, he realized he didn't have his phone. Sentence3: He spent an hour looking for it, but finally gave up. Sentence4: He sprinted to his class, remembering he was late. Sentence5: When he ran in the room, the professor gave him a dirty look.
Professor, John