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: Consider Input: Sentence1: Clayton was deathly afraid of house centipedes. Sentence2: One day he saw one scuttling around on his floor. Sentence3: Terrified, he called over his roommate to kill it for him. Sentence4: She walked in, unafraid, and swiftly smashed the bug with a book. Sentence5: Clayton was grateful and actually kind of impressed.

Output: Clayton, Roommate

Input: Consider Input: Sentence1: Joe imagined getting rich by finding a priceless pearl. Sentence2: He took his boat to an oyster bed and started looking. Sentence3: He tossed the oysters aside when he found no pearls inside. Sentence4: Hours later, Joe had nothing to show for his troubles. Sentence5: His stomach grumbled and Joe thought of the wasted oysters.

Output: Joe

Input: Consider Input: Sentence1: Boomer and Abby are my two puppies. Sentence2: They like to get into trouble. Sentence3: They are always trying to escape the backyard. Sentence4: One day I watched Boomer tunnel under the fence. Sentence5: He then ran to the front door and barked to let him in!
Output: I (myself), Abby, Boomer