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: Jake was lifting weights. Sentence2: He wanted to build some muscle. Sentence3: He was lifting some heavy dumbbells over his head. Sentence4: The dumbbell fell down and hit his knee. Sentence5: Jake couldn't do any leg exercises that day.
A:
Jake