Definition: 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: Sentence1: Mark just got a new job that pays more money. Sentence2: The only bad thing about it is that it's an overnight job. Sentence3: Mark starts work at ten at night and gets off at five in the morning. Sentence4: It took Mark a month to adjust his sleeping habits. Sentence5: Now Mark is a night owl who can sleep all day easily.
Output:
Mark