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: Martha is going camping. Sentence2: She has never been before. Sentence3: She is going with her husband. Sentence4: They get to the camp and set up the tent. Sentence5: Martha enjoys her time camping.
Example Output: Martha,s husband, Martha

Example Input: Sentence1: Matt's mom promised a surprise for him after school. Sentence2: He was excited all day. Sentence3: So excited that he wasn't paying attention during math class. Sentence4: When he didn't answer when called, he was given detention. Sentence5: Matt would have to wait longer to find out what was his surprise.
Example Output: Matt, Matt's mom

Example Input: Sentence1: Peter wanted to cosplay at a local convention. Sentence2: He researched his favorite characters and chose one of them. Sentence3: He spent hours creating his costume. Sentence4: When he arrived to the convention, everyone wanted to take pictures. Sentence5: Peter felt proud of his hand-made creation.
Example Output:
Peter