You will be given a definition of a task first, then some input of the task.
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: Amy was friends with Erin and Sara. Sentence2: Erin and Sara had been making fun of Amy in class one day. Sentence3: Amy decided she no longer wanted to be their friend. Sentence4: She walked into class and sat across the room. Sentence5: Amy knew she made the right choice as they to giggled and whispered.
Output:
Amy, Erin, Sara