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: Katie's birthday was coming up. Sentence2: Her best friend wanted to surprise her with a party. Sentence3: She got together with Katie's friends and family and made a plan. Sentence4: They decided to have Katie go to the store while they set up the party. Sentence5: They set up the party and surprised Katie when she came back.
Output:
Best friend, Katie's friends and family, Katie