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.
Input: Sentence1: Harry was making some spaghetti. Sentence2: The noodles were done before everything else. Sentence3: To keep them warm, he put the colander of noodles into the oven. Sentence4: When he wasn't looking, his roommate turned the oven on to cook. Sentence5: A few minutes later they saw that the colander had melted.
Output:
Roommate, Harry