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: Sam has a cat she loves more than anything. Sentence2: She is going on vacation and has to leave her cat behind. Sentence3: She gets a cat sitter to watch her cat. Sentence4: When sam comes back from vacation her cat is gone. Sentence5: Sam's cat was stolen!
Sitter, Vacation, Sam, Cat