Instructions: 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: Dustin notices that his car is filthy. Sentence2: It is strewn with fast food wrappers and coffee cups. Sentence3: Dustin spends one Sunday afternoon cleaning out his car. Sentence4: It takes longer than he expected. Sentence5: However, once it is clean, Dustin feels much better.
Output:
Dustin