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: Jim was sitting alone in his room, bored. Sentence2: He decided to go out and do something. Sentence3: He tagged the stop sign at the end of his street. Sentence4: A cop sat in his cruiser and watched him do it. Sentence5: Jim got sentenced to six months in juvenile detention.

Output: Cop, Jim

Input: Consider Input: Sentence1: Tre's bicycle really needed new brakes. Sentence2: Tre saved up all his allowance to take his bike to the shop. Sentence3: On the way a teenager jumped Tre and stole all his money and his bike. Sentence4: Tre walked home crying and empty handed. Sentence5: When he got there he found his mother dead.

Output: A teenager, His mother, Tre

Input: Consider Input: Sentence1: The mail service near me is three blocks away. Sentence2: I had to run down there for a package. Sentence3: On the way home, I noticed college kids drinking beer. Sentence4: I asked if they were of age, and they became angry. Sentence5: An angry, drunken mob of kids chased me to my door.
Output: I (myself), College kids