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.

Example Input: Sentence1: Sean was in a bad mood. Sentence2: And he realized that his room was a mess. Sentence3: He decided to clean up and organize everything. Sentence4: And his room looked beautiful. Sentence5: And Sean was in a bad mood less often.
Example Output: Sean

Example Input: Sentence1: Tom was at the beach with friends. Sentence2: He had too much fun and forgot to put sunscreen on. Sentence3: Within hours someone pointed out how red he was. Sentence4: Tom was severely sunburned. Sentence5: He had to leave and get special healing lotion.
Example Output: Friends, Someone, Tom

Example Input: Sentence1: I used to smoke when I was younger. Sentence2: No matter the weather I never smoked inside. Sentence3: One day I was lighting a cigarette as i walked out the door. Sentence4: I looked up and saw three federal agents standing next to me. Sentence5: It turned out they were looking for the previous tenant.
Example Output:
I (myself), Three federal agents