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: Kathie fell from her bicycle. Sentence2: She bumped her head pretty hard on the ground. Sentence3: Kathie stood up dazed. Sentence4: A stranger escorted her to a hospital. Sentence5: Kathie was treated for a mild concussion.

Output: A stranger, Kathie

Input: Consider Input: Sentence1: Simon invited his friend Joey over for a play-date. Sentence2: He was looking forward to playing Minecraft with his friend. Sentence3: Right before Joey arrived, the internet went out. Sentence4: Simon tried resetting the router, but it didn't help. Sentence5: Simon and Joey played outside until the router was back online.

Output: Simon, Joey

Input: Consider Input: Sentence1: Shane was eating at a high end restaurant. Sentence2: The restaurant was new and was very crowded. Sentence3: He waited while to get his drink order. Sentence4: His server did the best they could but Shane was not happy. Sentence5: Shane decided to leave a very low tip.
Output: Shane, Server