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.

Example Input: Sentence1: The man apologized. Sentence2: The woman said she accepted. Sentence3: The two talked for a while. Sentence4: The man excused himself. Sentence5: He could tell his company was not wanted.
Example Output: Woman, Woman

Example Input: Sentence1: I was playing music on my CD player. Sentence2: I dropped the CD player. Sentence3: It didn't play music anymore. Sentence4: Then I found twenty dollars on the ground. Sentence5: I was able to buy a new CD player.
Example Output: I (myself)

Example Input: Sentence1: Leo was trying to learn a piano piece he liked. Sentence2: But it was too advanced for him. Sentence3: Nevertheless, he practiced it everyday for weeks. Sentence4: But when his piano teacher heard, he suggested practicing the basics. Sentence5: After practicing easier pieces for months, everything became easier.
Example Output:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Leo's piano teacher, Leo

