Definition: 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: Lisa's mom promised her a new bike if she got all A's. Sentence2: She worked harder than ever. Sentence3: When she got her report card, she had four As and one B plus. Sentence4: She was so disappointed she wouldn't be getting her bike. Sentence5: Her mom was still proud of her grades, so she got it anyway.
Output:
Lisa's mom, Lisa