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: Bonnie had been hiking all day. Sentence2: She went home to take a shower. Sentence3: She couldn't wait to get all the dirt off of her. Sentence4: She turned the knob but nothing happened. Sentence5: The water had been shut off!
Example Output: Bonnie

Example Input: Sentence1: Jim's son is afraid to fly. Sentence2: He's seen too many stories about plane crashes. Sentence3: He can't sleep the night before they are set to fly to Denver. Sentence4: But by the time he gets on the plane he is exhausted. Sentence5: He is so tired that he sleeps all the way through the flight.
Example Output: Jim's son

Example Input: Sentence1: Olivia was looking to buy a car. Sentence2: Her friend's brother was selling a used car. Sentence3: Olivia went to see her the car. Sentence4: Olivia and the guy decided on a price for the car. Sentence5: Olivia bought the car.
Example Output:
Friend's brother, Olivia, Friend