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: Ben needed to lose weight. Sentence2: He bought a gym membership last week. Sentence3: When he went to the gym, he realized how weak he was. Sentence4: He could not even bench press eighty pounds. Sentence5: However, Ben seems willing to keep up with his workout schedule.
Output:
Ben