Given the task definition and input, reply with output. 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: Joe imagined getting rich by finding a priceless pearl. Sentence2: He took his boat to an oyster bed and started looking. Sentence3: He tossed the oysters aside when he found no pearls inside. Sentence4: Hours later, Joe had nothing to show for his troubles. Sentence5: His stomach grumbled and Joe thought of the wasted oysters.
Joe