#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <time.h>
#include <cstdlib>
#include <cmath>
#include <fstream>
#include <iomanip>

int main(void) {

	//test用
	//std::ifstream in("test.txt");
	//std::cin.rdbuf(in.rdbuf());

	int N;
	std::cin >> N;

	int count = 0;
	int num = 1;

	while (num < N) {
		count++;
		num *= 2;
	}

	std::cout << count << std::endl;
}