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.
Q: Sentence1: Paul maintained a small business's server room. Sentence2: He was puzzled why their machines would reboot every night. Sentence3: Finally he spent the night at work watching what happened. Sentence4: Paul saw the janitor come in and remove the power cables. Sentence5: He realized his mistake of not keeping the server room locked.
A:
Paul, Janitor, Small business