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: Christina converted to Islam when she was in college. Sentence2: Before she converted, she read a lot about Islam. Sentence3: She found out that Muslims should not have names like hers. Sentence4: Christina means follower of Christ which is not in line with Islam. Sentence5: Christina changed her name to Charity.
Example Output: Christina, Charity

Example Input: Sentence1: Rakesh was 10-years-old and his parents owned a motel. Sentence2: They believed their son Rakesh should have money to buy things. Sentence3: Rakesh bought toys from the hobby store, but his friend didn't. Sentence4: Rakesh gave his friend, Charles, $75! Sentence5: But Charles showed his mother the cash and she made him return it.
Example Output: His parents, Motel, Rakesh, His mother

Example Input: Sentence1: Carla wanted to be more active. Sentence2: Her friend suggest she start biking with her at the local park. Sentence3: Carla went to the store to buy a bike. Sentence4: She found a bike she liked and bought it. Sentence5: Carla began riding with her friend that day.
Example Output:
Carla, Friend