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: It was early December. Sentence2: My mom had been fighting cancer. Sentence3: She knew her time was near. Sentence4: She promised she would look after me in heaven. Sentence5: She died in her sleep.
Example Output: I (myself), My mom

Example Input: Sentence1: I needed to get groceries yesterday. Sentence2: I walked to the store instead of driving. Sentence3: On the way, I thought about what I needed to buy. Sentence4: I took my list into the store with me. Sentence5: I bought everything on the list, and had trouble carrying it home.
Example Output: I (myself)

Example Input: Sentence1: Howard drilled holes through the tiles for the masonry pins. Sentence2: He used a level to make sure they were lined up to a T. Sentence3: The homeowner offered suggestions and was otherwise a nuisance. Sentence4: Howard didn't mind, and explained why he was doing it the way he was. Sentence5: The homeowner paid Howard a bonus for his careful and attentive work.
Example Output:
Homeowner, Howard