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 had a great time on my birthday, with emails and cards from friends. Sentence2: My boss told me I could go home early, which surprised me. Sentence3: When I drove home, I had a hard time finding a place to park. Sentence4: When I got to my front door, I heard voices inside my apartment. Sentence5: I opened the front door and everyone laughed with surprise.
A:
I (myself), Friends, Boss