#include <iostream>
int main(void) {
	unsigned int N;
	int a;
	std::cin >> N;
	N--;
	a=N?0:-1;
	if(0xFFFF0000&N){N>>=16;a+=16;}
	if(0xFF00&N){N>>=8;a+=8;}
	if(0xF0&N){N>>=4;a+=4;}
	if(0xC&N){N>>=2;a+=2;}
	a+=((0x2&N)>>1)+1;
	std::cout << a << std::endl;
}