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.

Example Input: Sentence1: Tim bet his friend Todd that he couldn't eat a grasshopper. Sentence2: Tim caught a large green grasshopper in his front lawn. Sentence3: Tim teased Todd for hours. Sentence4: Finally Todd gave in and ate the grasshopper. Sentence5: He spit it out because it tasted so disgusting.
Example Output: Tim, Grasshopper, Friend

Example Input: Sentence1: Jemma was looking forward to going to the lake today. Sentence2: However, she saw that it was going to rainy today. Sentence3: Upset, she thought about other things she could do today instead. Sentence4: She called a few of her friends and asked them to come over. Sentence5: Jemma and her friends spent the rest of the day watching movies.
Example Output: Her friends, Jemma

Example Input: Sentence1: Clare found the letter. Sentence2: She opened it up. Sentence3: Inside was a small note. Sentence4: She threw the note away. Sentence5: She kept the envelope to use.
Example Output:
Clare