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: Ken is a DJ for a club. Sentence2: Last night he had a really annoying patron. Sentence3: They kept asking for different songs. Sentence4: Ken kept having to turn him down. Sentence5: Eventually he just ignored him completely.

Ex Output:
Ken, Annoying patron

Ex 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!

Ex Output:
Jacob, Vet, Dog

Ex Input:
Sentence1: Charles had always been the best pool player in his group of friends Sentence2: One day, a new person appeared and challenged Charles to a game Sentence3: They had a good game, but Charles lost in the end Sentence4: He realized that he didn't always have to be so competitive Sentence5: He became a better friend to his friends, and a better person

Ex Output:
Charles, Friends, New person