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.

Sentence1: At 11 years old, I always wanted a pet. Sentence2: One day, a boy rode his bike down my street, with a box in his lap. Sentence3: He opened the shoe box, and threw out a ferret into the ditch. Sentence4: I raced out and scooped up the ferret, taking it home. Sentence5: We called the police, and they said I could keep it.
I (myself), Boy, Pet, Police