What is the complexity of the below code?

int pow$($int $m,$ int $n)\{$

int ret $=1$;

int $k=m$;

int $i=n$;

while

if $(i\%2==1)$ ret ${?}^{**}=k$;

$k^{**}=k$;

$\frac{i}{?}=2$;

$\}$

return ret;

$\}$

Your answer:

$O(n)$

$O(m)$

$O(nlogn)$

$O(logn)$

$O(n^2)$