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: Jacob noticed his dog was whining. Sentence2: Jacob investigated and found his dog's leg hurt. Sentence3: He took the dog to see the vet. Sentence4: The vet made a cast to set the hurt leg. Sentence5: Within a few weeks, Jacob and his dog were playing again!
Example Output: Jacob, Vet, Dog

Example Input: Sentence1: Connie has not studied for her exams. Sentence2: In a panic she sits near the smartest girl in glass. Sentence3: As the exam is handed out she slowly works through her exam. Sentence4: She's copying the girl next to her. Sentence5: Connie gets caught and is expelled from university.
Example Output: Smartest girl, Connie

Example Input: Sentence1: Corey went to see a movie at the theatre. Sentence2: The movie began playing. Sentence3: Ten minutes into the movie, the film malfunctioned. Sentence4: Everyone was given their money back. Sentence5: Corey returned to the movies the next week.
Example Output:
Corey