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: Raj formed a band with his friends. Sentence2: They would practice in their garages. Sentence3: One day, a neighbor called to complain. Sentence4: The police told the band they'd have to quiet it down. Sentence5: The band decided to take up poetry reciting instead.

Output: Friends, Raj, Neighbor, Police

Input: Consider Input: Sentence1: Barry took a science class. Sentence2: He didn't expect an essay. Sentence3: He took a test with one. Sentence4: He did his very best. Sentence5: Barry didn't do so well.

Output: Barry, Science class

Input: Consider Input: Sentence1: Yesterday, Greg woke up feeling ill. Sentence2: He had a headache and felt nauseous. Sentence3: He went to the doctor to get it checked out. Sentence4: The doctor told him he had the flu. Sentence5: He spent the rest of the day resting to get better.
Output: Greg, Doctor