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.

Example Input: Sentence1: On a very hot day, Steve was outside with his dog when his phone rang. Sentence2: A friend urgently needed him, and Steve jumped in his car to go help. Sentence3: He texted his wife to let the dog in and spent hours with his friend. Sentence4: Coming home, he was horrified to see his dog motionless in the dirt. Sentence5: His wife never got the text, and trapped outside, the dog had died.
Example Output: Steve, His dog, His friend, His wife

Example Input: Sentence1: David was whistling in class. Sentence2: The teacher didn't know who was making the noise. Sentence3: She didn't know who to punish. Sentence4: One of the students told the teacher after class that it was David. Sentence5: The next time David whistled, the teacher blamed David.
Example Output: One of the students, Teacher, David

Example Input: Sentence1: Jane was excited about her class trip. Sentence2: They were going to New York City. Sentence3: She had never been before. Sentence4: The class arrived by bus. Sentence5: The city was so much bigger than Jane had imagined.
Example Output:
Jane, The class