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: Ruth was visiting her grandfather's farm. Sentence2: She liked animals but the tall horses scared her. Sentence3: Ruth's grandpa brought her to one of the horses. Sentence4: He showed Ruth that the horse was kind and gentle. Sentence5: Soon Ruth felt much less scared and calmed down.

Output: Ruth, Grandpa

Input: Consider Input: Sentence1: Troy had not seen his family in years. Sentence2: Troy had been living in another country. Sentence3: He longed to see his family. Sentence4: He bought a plane ticket. Sentence5: He visited his family on Thanksgiving.

Output: Troy, Family

Input: Consider Input: Sentence1: Mary always wanted to be a ballerina. Sentence2: Her parents signed her up for dance lessons. Sentence3: Mary worked very hard in the classes and at home. Sentence4: Mary got the lead part in the dance recital that year. Sentence5: Mary's dancing received a standing ovation at the recital!
Output: Her parents, Mary