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.

Input: Consider Input: Sentence1: Ken was a cook. Sentence2: Ken was given an order for a medium rare steak. Sentence3: Ken cooked up the steak nice and rare. Sentence4: He went to serve it to the customers. Sentence5: The customer told him they wanted it well done.

Output: Customer, Ken, Customers

Input: Consider Input: Sentence1: Iris put on blue contacts. Sentence2: She looked at herself in the mirror. Sentence3: She thought she looked weird. Sentence4: She replaced the contacts. Sentence5: She thought she looked better in brown.

Output: Iris

Input: Consider Input: Sentence1: After weeks of practice, the band was playing its first football game. Sentence2: A number of members were freshman. Sentence3: Many of them were very nervous! Sentence4: But when they marched out they all did a great job. Sentence5: A few sour notes, but no one seemed to notice!
Output: Members, The band