Q: 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: Sam worked nights and slept during the day. Sentence2: Sam met a girl but she worked during the day. Sentence3: Sam was too tired often to go to work at night. Sentence4: Sam asked to be switched to the day shift. Sentence5: Sam was no longer tired when he was with his girlfriend.
A:
Sam