Detailed Instructions: 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.
Problem:Sentence1: Once a little girl got a puppy for Christmas. Sentence2: It was hidden inside a big red box. Sentence3: When she opened it she was very surprised! Sentence4: One day the puppy went missing. Sentence5: They found it in the big red box after all!
Solution:
Little girl, Puppy