Given the task definition and input, reply with output. 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: Sid rode his bike to his friend's house. Sentence2: Sid left his bike on the sidewalk near the street. Sentence3: When Sid came out to go home his bike was missing! Sentence4: Sid thought his bike had been stolen. Sentence5: But Sid's mom had driven by and taken the bike home.
Sid's mom, Friend, Sid