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: On a Friday night, Bobby wanted to hang out with his friends. Sentence2: All of his friends were busy tonight though. Sentence3: So Bobby made imaginary friends. Sentence4: Bobby hung out with his imaginary friends. Sentence5: Later Bobby went to sleep and was happy with his new squad.

Output: Friends, Imaginary friends, Bobby

Input: Consider Input: Sentence1: Simon didn't like anyone and no one liked him either. Sentence2: He was mean and liked to hurt little animals. Sentence3: One day, a young boy went to him with a frog. Sentence4: Simon took the frog and was about to hurt it when the boy screamed. Sentence5: Simon was so touched, he put the frog on the ground and left.

Output: Boy, Simon, Frog

Input: Consider Input: Sentence1: Teddy was happy to be going with his family on a trip. Sentence2: He had never been on a train before. Sentence3: They boarded and found their seats. Sentence4: Teddy looked out the window with glee. Sentence5: He was having such a great time.
Output: His family, Teddy