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: She opened the back door and propped it. Sentence2: The dog didn't notice. Sentence3: A loud noise got her attention. Sentence4: It was a bird in the backyard. Sentence5: She ran outside to check it out.

Output: Dog, Bird

Input: Consider Input: Sentence1: Neil was touring Istanbul. Sentence2: He joined his tour group in the morning. Sentence3: Then he went with them from stop to stop. Sentence4: He learned so much about Turkish history. Sentence5: Neil really loved his tour through Istanbul!

Output: Neil

Input: Consider Input: Sentence1: Rick was visiting his grandma. Sentence2: He and his dad went into the yard to play. Sentence3: The grass in the yard was tall and needed to be cut. Sentence4: Later that night Rick was itchy from playing in the grass. Sentence5: Rick scratched and scratched until daddy gave him a bath.
Output: His dad, Rick, Grandma