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: Carl was passionate about computers. Sentence2: He took many classes about computer programming. Sentence3: He decided to build a computer himself. Sentence4: He spent many hours researching and planning the computer. Sentence5: He successfully built the computer and saved a lot of money doing so.

Output: Carl

Input: Consider Input: Sentence1: Isaac was prone to bouts of depression. Sentence2: He never made many friends, and was usually found by himself. Sentence3: He imagined that no one would miss him and began to cry. Sentence4: His mother heard his sobbing and came to find out what was wrong. Sentence5: She encouraged him that she would miss him if he disappeared.

Output: Isaac, Friends, Mother

Input: Consider Input: Sentence1: Alicia decided to participate in the fun run. Sentence2: She got a team of friends together. Sentence3: During the run, she got exhausted. Sentence4: It was a workout. Sentence5: Alicia got in third place.
Output: Alicia, Friends