He got 2*12=<<2*12=24>>24 cookies

So he has 24-3=<<24-3=21>>21 cookies left

# Answer

21
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
John buys 2 dozen cookies.  He eats 3.  How many cookies does he have left?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
21
John buys 2 dozen cookies.  He eats 3.  How many cookies does he have left?
train