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: A cat ran around the room. Sentence2: He quickly tired from running. Sentence3: He curled up on the couch. Sentence4: The cat slept all afternoon. Sentence5: When he woke up, he was ready to run around again.
Output:
Cat