Q: 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.
Sentence1: A supermarket clerk was busy setting up a display of boxes. Sentence2: He finished by carefully balancing the last boxes on top. Sentence3: He stood back and admired his tower. Sentence4: A customer ran out of nowhere and drove into the display. Sentence5: Boxes tumbled down as he laughed like a loon.
A:
Customer, Supermarket clerk