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: Consider Input: 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.

Output: Sam

Input: Consider Input: Sentence1: Cat loved bold makeup. Sentence2: She bought some bright red lipstick. Sentence3: She carefully applied it to her lips. Sentence4: Her friends all complimented the look. Sentence5: Cat felt confident and beautiful.

Output: Friends, Cat

Input: Consider Input: Sentence1: The man called for his dog. Sentence2: His dog did not come. Sentence3: He looked around the yard for the dog. Sentence4: He could not find the dog. Sentence5: He called animal control to report the dog missing.
Output: Animal control, Dog, Man