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: Ed was in the Army. Sentence2: He sent letters to his girl but they never came. Sentence3: Then he came home on leave and ten letters arrived. Sentence4: They had been held up at the post office. Sentence5: His girl got to read all ten letters at once!
Output:
Ed, Girl