Detailed Instructions: 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.
Q: Sentence1: Amy worked from home and had a question. Sentence2: She asked in the chat room and waited for a response. Sentence3: The supervisor was helping someone else with a complex issue. Sentence4: After 20 minutes she helped Amy. Sentence5: Amy kept her caller informed of the delay and avoided escalation.
A:
Amy, Caller, Supervisor