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: Marcus was playing his guitar at school. Sentence2: His friend Matthew approached him and asked about the music. Sentence3: Soon they were in a heated conversation about their music tastes. Sentence4: The duo decided that they should collaborate on some music. Sentence5: The resulting album was very popular with all of their friends.

Ex Output:
Marcus, Their friends, Matthew

Ex Input:
Sentence1: Tucker has always been lazy when it comes to chores. Sentence2: He now lives alone after a great 18 years living with his parents. Sentence3: In his college dorm, he would cook food but rarely ever do the dishes. Sentence4: After being gone for the weekend, his roommate returns to a smell. Sentence5: Tucker was scolded by his roommate for the dirty dishes in the sink.

Ex Output:
Tucker, Parents, Roommate

Ex Input:
Sentence1: Lisa had never ridden a horse. Sentence2: She wanted to try horseback riding this summer. Sentence3: Her friend invited her to visit her farm. Sentence4: Lisa went and rode the three horses they kept there. Sentence5: She was proud of herself for trying something new.

Ex Output:
Lisa, Friend