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: Iris put on blue contacts. Sentence2: She looked at herself in the mirror. Sentence3: She thought she looked weird. Sentence4: She replaced the contacts. Sentence5: She thought she looked better in brown.

Output: Iris

Input: Consider Input: Sentence1: Don showed up for his clarinet lesson. Sentence2: He forgot to bring his music. Sentence3: A teacher told him to play some scales. Sentence4: Don really was not ready for that. Sentence5: After that they played some duets with teacher.

Output: Don, Teacher

Input: Consider Input: Sentence1: Jenny's family arrived late to the parade! Sentence2: She was so small she would never be able to see anything. Sentence3: They had to stand all the way in the back! Sentence4: Fortunately her father was very tall! Sentence5: He lifted her onto his shoulders so she could see the action.
Output: Father, Family