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: I noticed that the roof to my house was leaking. Sentence2: I got a ladder to fix it. Sentence3: I slipped off of the ladder and hurt my leg. Sentence4: The pain made me howl loudly. Sentence5: I learned that I should just call a professional next time.
A:
I (myself), Professional