Evaluate $\log_2 (4^2)$.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Evaluate $\log_2 (4^2)$.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
4
Evaluate $\log_2 (4^2)$.
train