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.

Ex Input:
Sentence1: James lives in Texas. Sentence2: Texas is prone to tornados. Sentence3: James prepared for this. Sentence4: He bought a tornado shelter. Sentence5: So when a tornado strikes he will be safe.

Ex Output:
James

Ex Input:
Sentence1: In college, I studied abroad in France. Sentence2: My 16-year-old host brother was very nice. Sentence3: I invited him to a party with me to meet some cool older kids. Sentence4: He misunderstood why I invited him. Sentence5: He tried to kiss me on the bus ride home.

Ex Output:
I (myself), Host brother, Older kids

Ex 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.

Ex Output:
Greta, Greta's son, The doctor