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.

Ex Input:
Sentence1: Jim liked to watch sports, but never played. Sentence2: He mostly wished he was better at basketball. Sentence3: Jim's friends eventually encouraged him to join the basketball team. Sentence4: After lots of practice, Jim's skills increased. Sentence5: Now Jim is the best player on the team, and he feels accomplished.

Ex Output:
Jim, Jim's friends

Ex Input:
Sentence1: Marie was stuck in traffic and playing a game on her phone. Sentence2: Someone tapped on her window and she recognized a cop. Sentence3: He told her to stop playing and pay attention. Sentence4: She apologized and pocketed her phone. Sentence5: She regretted it as it took an hour for the traffic to move again.

Ex Output:
Cop, Marie

Ex Input:
Sentence1: Robby stopped at a gas station in a small town. Sentence2: There was no one in the store that he saw working. Sentence3: Robby looked around the store. Sentence4: He saw an old man passed out on the floor. Sentence5: Robby called an ambulance to help the man.

Ex Output:
Old man, Robby