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: The new cook in the restaurant wanted to prove himself. Sentence2: He challenged the head chef to a knife skills contest. Sentence3: They both had to chop up two onions as fast as they could. Sentence4: The new cook was quick but was not fast enough. Sentence5: The head chef told the new cook that he did a good job.
A:
Cook, Chef