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: Doug is cleaning his house. Sentence2: Doug wants everything perfect. Sentence3: He begins vacuuming the floor. Sentence4: He cleans the whole house. Sentence5: Doug is happy with is clean house.
Student:
Doug