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: Michelle decides to skip some rocks at the pond. Sentence2: She is impressed by how far they skip. Sentence3: Some of the rocks go halfway across the pond. Sentence4: Later on she goes back home. Sentence5: Michelle is happy the went to the pond to skip rocks.

Output: Michelle

Input: Consider Input: Sentence1: Amy loved The Babysitters Club books when in elementary school. Sentence2: When she was 17 they made a movie. Sentence3: A friend suggested she see it. Sentence4: Amy felt she was way too adult to see that movie. Sentence5: At the theater she decided to see a Pg13 movie instead.

Output: Amy, Friend

Input: Consider Input: Sentence1: Jeff just turned 21. Sentence2: So he decided to try some alcohol. Sentence3: He became addicted and drank alcohol every day. Sentence4: But his family intervened. Sentence5: It took years for Jeff to get over his addiction.
Output: Family, Jeff