Teacher: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.
Teacher: Now, understand the problem? Solve this instance: Sentence1: Sam was over at a friend's apartment. Sentence2: He got a drink out of the refrigerator. Sentence3: Sam placed the drink directly on his friend's coffee table. Sentence4: The friend asked him if he could use a coaster. Sentence5: Sam apologized and obliged.
Student:
Friend, Sam