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: Iris put on blue contacts. Sentence2: She looked at herself in the mirror. Sentence3: She thought she looked weird. Sentence4: She replaced the contacts. Sentence5: She thought she looked better in brown.
Example Output: Iris

Example Input: Sentence1: Karen liked a diner in her town. Sentence2: She loved their burgers. Sentence3: The diner changed their recipe for the burgers. Sentence4: Karen didn't like the new recipe. Sentence5: She stopped going to the diner.
Example Output: Karen

Example Input: Sentence1: An old man walked through a large park in the city. Sentence2: He began to feel tired so he looked for a bench. Sentence3: Nearby was a bench with some young people sitting on it. Sentence4: The old man was too bashful to ask for them to get up. Sentence5: The young noticed his suffering and stood up anyway.
Example Output:
Old man, Young people