Given the task definition and input, reply with output. 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.

Sentence1: I spent an entire week eating nothing but pizza. Sentence2: Soon, my stomach started hurting. Sentence3: I did not want to give up the pizza. Sentence4: My friend decided to come over and cook for me. Sentence5: The food was so delicious, that I gave up pizza for good.
I (myself), Friend