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: Charles was obsessed with crossword puzzles. Sentence2: Every morning, Charles would attempt the New York Times crossword. Sentence3: He loved the challenge of completing the daily crossword. Sentence4: There are days where Charles cannot complete the crossword puzzle. Sentence5: However, since Charles loves crosswords, he continues to attempt them.
Output:
Charles