Q: 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: When I was a boy my parents used to take my brother and I to the park. Sentence2: We would play and have a lunch and just walk around. Sentence3: One day the park all the picnic benches were full we had one. Sentence4: These two police officers has come up and ask if they could join us. Sentence5: After they had lets us operate the police car lights and siren .
A:
Boy, Parents, Brother, Police officers