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.

Input: Consider Input: Sentence1: Tommy has a red balloon. Sentence2: It's his favorite color! Sentence3: But one day, the balloon lost it's air. Sentence4: Tommy was very sad. Sentence5: But he'll get a new balloon tomorrow, so it's not that bad.

Output: Tommy

Input: Consider Input: Sentence1: Jill had set a goal for herself in the seventh grade. Sentence2: She maintained the highest grades ever since then. Sentence3: She was determined to be valedictorian. Sentence4: When she became a senior, she still had that goal. Sentence5: At graduation, she met her goal and presented her speech.

Output: Jill

Input: Consider Input: Sentence1: Cassie did not like taking baths. Sentence2: Her mom was frustrated because Cassie was starting to stink. Sentence3: One day her mom bought Cassie a bath toy. Sentence4: Cassie wanted to play with the toy so agreed to take a bath. Sentence5: Her mom was so happy to have a clean daughter.
Output: Mom, Cassie