#include<iostream>
using namespace std;
int Log2(unsigned int x)
{
    int res;
    asm volatile("bsrl %1,%%eax":"=a"(res):"m"(x));
    return res;
}
int main() {
	int x;
	scanf("%d",&x);
	printf("%d\n",Log2(x));
	return 0;
}