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: Diana sacrificed her sleep to study for her math exam. Sentence2: At one moment, she fell asleep on her table. Sentence3: Diana's mom woke her up in the morning. Sentence4: Diana got mad when she found out that she's late to her exam. Sentence5: She also missed it since there was several traffic on the road.
Example Output: Diana, Diana's mom

Example Input: Sentence1: The sink in my bathroom broke. Sentence2: I decided that I should fix it myself. Sentence3: After one hour, the sink looked worse than before. Sentence4: I finally decided to call a professional plumber. Sentence5: The plumber fixed the sink in ten minutes.
Example Output: I (myself), Professional plumber

Example Input: Sentence1: My son-in-law turned 33 today. Sentence2: My son sent him a tribute. Sentence3: They both love the tv show The Office. Sentence4: My son sent a photo of a birthday slogan from an episode. Sentence5: My son-in-law was pleased.
Example Output:
My son-in-law, My son