Evaluate \[\sqrt{5 + \sqrt{21}} + \sqrt{5 - \sqrt{21}}.\]
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Evaluate \[\sqrt{5 + \sqrt{21}} + \sqrt{5 - \sqrt{21}}.\]
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
\sqrt{14}
Evaluate \[\sqrt{5 + \sqrt{21}} + \sqrt{5 - \sqrt{21}}.\]
train