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.
Q: Sentence1: John all night doing his home work. Sentence2: He was glad to finish it and go to bed. Sentence3: John woke up to find his homework had been torn to pieces. Sentence4: His dog had eat his homework. Sentence5: John was furious and spent the morning doing his homework again.
A:
John, Dog