Find $\cos^{-1} \frac{1}{2}.$  Express your answer in radians.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Find $\cos^{-1} \frac{1}{2}.$  Express your answer in radians.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
\frac{\pi}{3}
Find $\cos^{-1} \frac{1}{2}.$  Express your answer in radians.
train