What is the time complexity of the following algorithm?

long foo$($int $N)$

$\{$

Count$++$;

if $(N==0)$

return $1$;

else

return foo $(\frac{N}{2})**N$;

$\}$

O$(1)$

$O(N)$

$O(N^{{?}^{{?}^{?}}}2)$

$O(logN)$