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.
Problem:Sentence1: Alex was asleep in the nurse's office at school. Sentence2: He awoke to see his dad waiting for him. Sentence3: His dad was an hour late. Sentence4: Alex was mad at his father for making him wait. Sentence5: Dad bought Alex pizza to make up for being late.
Solution:
Dad, Alex