For how many positive integers $n$ is $n^2-3n+2$ a prime number?
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
For how many positive integers $n$ is $n^2-3n+2$ a prime number?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
1
For how many positive integers $n$ is $n^2-3n+2$ a prime number?
train