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: Cathy was looking for ideas for the school fair. Sentence2: Cathy decided it would be fun to have a dunk tank. Sentence3: Cathy choose the principal, and the vice principal to be in the tank. Sentence4: At the fair, the dunk tank was a hit. Sentence5: Cathy was glad to see the tank was such a success.
Cathy, Vice principal, Vice principal