#include <iostream>		//cin, cout
#include <vector>		//vector
#include <algorithm>	//sort,min,max,count
#include <string>		//string,getline, to_string

using namespace std;

int main() {

	int N;
	cin >> N;

	int temp = 1;
	int ans = 0;

	while (temp < N) {
		temp = temp * 2;
		ans++;
	}

	cout << ans << endl;

	return 0;

}