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: Jim had lost his cellphone. Sentence2: He searched for hours every where. Sentence3: He decided to call his school. Sentence4: The secretary looked in the lost in found at his school. Sentence5: She found the exact phone he was looking for.
Output:
Jim, Secretary