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: Neil was touring Istanbul. Sentence2: He joined his tour group in the morning. Sentence3: Then he went with them from stop to stop. Sentence4: He learned so much about Turkish history. Sentence5: Neil really loved his tour through Istanbul!
Example Output: Neil

Example Input: Sentence1: Greta had noticed her son was having trouble focusing in school. Sentence2: Greta took her son to the doctor. Sentence3: The doctor diagnosed the boy with ADHD. Sentence4: The doctor prescribed medicine for him. Sentence5: Greta's son now focuses much better in class.
Example Output: Greta, Greta's son, The doctor

Example Input: Sentence1: I went on a trip to the Lake the other day. Sentence2: I went with a lot of my friends. Sentence3: We spent the whole week partying and fishing. Sentence4: It was a great time. Sentence5: I can't wait to do it again next year.
Example Output:
I (myself)