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: James lives in Texas. Sentence2: Texas is prone to tornados. Sentence3: James prepared for this. Sentence4: He bought a tornado shelter. Sentence5: So when a tornado strikes he will be safe.
Example Output: James

Example Input: Sentence1: Barry recently had to take a reading test for college. Sentence2: Barry was nervous, as he did not know what was on the test. Sentence3: However, as Barry was taking the test, he realized how much he knew. Sentence4: As the test went along, Barry felt more confident about it. Sentence5: Barry knew that he had passed the reading test he took.
Example Output: Barry

Example Input: Sentence1: Lindy struggled with math. Sentence2: Her teacher finally recommended another student tudor her. Sentence3: They worked together for days before the next test. Sentence4: Lindy felt confident as the teacher handed out the tests. Sentence5: Two days later she got her test back with a perfect score!
Example Output:
Lindy, Student, Her teacher