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: Bill was walking up the steps and texting at the same time. Sentence2: Suddenly Bill tripped. Sentence3: Bill's phone went flying and landed on the floor with a loud thud. Sentence4: When he picked it up the screen was smashed. Sentence5: The next day Bill bought a new phone.
Output:
Bill