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: Jim was sledding with his friend Anthony. Sentence2: Anthony dared him to go down the big hill. Sentence3: Jim took up the dare and as he was going he fell out of the sled. Sentence4: Jim rolled a few times as the unmanned sled flew into the river. Sentence5: Jim was ok, and the two of them went home for the day.
Example Output: Anthony, Jim

Example Input: Sentence1: When Poppy was growing up, she had a very special doll. Sentence2: She took the doll with her everywhere. Sentence3: As she got older, her mother tried to make her give up the doll. Sentence4: Poppy hid the doll so her mother couldn't find it. Sentence5: But Poppy's dog found the doll and chewed it to pieces.
Example Output: Poppy, Dog, Mother

Example Input: Sentence1: Ted had a toothache and went to see the dentist. Sentence2: In the office, the dentist took a look at Ted's teeth. Sentence3: He chastised Ted for not brushing well. Sentence4: Ted apologized but was impatient and angry. Sentence5: Ted left the visit with his tooth fixed but none the wiser.
Example Output:
Dentist, Ted