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: Brian has dreamed for many Years of going back graduate school. Sentence2: He starts by studying for a standardized test. Sentence3: He takes the test and gets a terrific score. Sentence4: Now Brian is ready to apply to school. Sentence5: He applies and is accepted at his first choice graduate school.
Brian