What is the sum of the largest and smallest prime factors of 990?
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
What is the sum of the largest and smallest prime factors of 990?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
13
What is the sum of the largest and smallest prime factors of 990?
train