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: When I was little I used to chew my fingernails as a habit. Sentence2: My mom told me if I continued doing this it would make me really fat. Sentence3: Her plan worked, as my fear of getting huge stopped my nasty habit. Sentence4: Well, one day we saw our neighbor in the store, being quite pregnant. Sentence5: I pointed at her belly, saying I knew what she had been doing!

Ex Output:
I (myself), Neighbor, Mom

Ex Input:
Sentence1: Don showed up for his clarinet lesson. Sentence2: He forgot to bring his music. Sentence3: A teacher told him to play some scales. Sentence4: Don really was not ready for that. Sentence5: After that they played some duets with teacher.

Ex Output:
Don, Teacher

Ex Input:
Sentence1: Kim was a single mom with twin girls. Sentence2: She worked two jobs, cleaning and waitressing. Sentence3: One night a customer forgot his wallet at the dining table. Sentence4: Kim , honest, hurried to chase him down and return it. Sentence5: The man was so impressed at her honesty, he handed her a $150 tip!

Ex Output:
Customer, Twin girls, Kim