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.
Input: Sentence1: Ai was a sheltered child who had been abused for years. Sentence2: In foster care she was silent and never smiled. Sentence3: Then one day her foster mom brought home a new baby girl! Sentence4: Ai played with the baby all day, teaching her things. Sentence5: And one day their mom found both little girls laughing together!
Output:
Ai, Baby girl, Foster mom