Detailed Instructions: 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.
Problem:Sentence1: Mary had always wanted a dog. Sentence2: Mary's mother would never allow her to have a pet. Sentence3: One day, a dog followed Mary's mother home from the grocery store. Sentence4: The dog would not go away, but laid down on Mary's mother's' feet. Sentence5: The dog got to stay, and Mary got a new pet.
Solution:
Mother, Mary, Dog