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: I used to deliver fliers everyday in the hot sun. Sentence2: My water bottle always ended up really hot. Sentence3: When I put ice in it, the ice melted. Sentence4: I decided to buy a special thermos that kept the cold in. Sentence5: Now I always had cold water when I was in the hot sun.

Ex Output:
I (myself)

Ex Input:
Sentence1: A young girl was at the grocery store after work one night. Sentence2: She had made a list and wanted to hurry home. Sentence3: When she was looking at the list a man bumped into to her. Sentence4: She looked up and smiled. Sentence5: The man then asked her out to dinner.

Ex Output:
A man, A young girl

Ex Input:
Sentence1: Linda was angry. Sentence2: She had lost her keys. Sentence3: She could not find them anywhere. Sentence4: She was about to give up hope. Sentence5: As Linda sat down on a chair, she spotted them on the floor.

Ex Output:
Linda