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: Polly loved cats. Sentence2: She didn't have a cat and wanted to adopt one. Sentence3: Polly learned that a friend of hers was fostering kittens. Sentence4: Polly went to her friend's house and met all the kittens there. Sentence5: She bonded with two of them and adopted them on the spot!
Output:
Polly, Friend, Kittens