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: Sam had a big exam for an important college course. Sentence2: He studied hard and went to every class. Sentence3: On the day of the exam he noticed the room was empty. Sentence4: The time and location had been changed. Sentence5: He never bothered to check his email and didn't know.
A:
Sam