#include <iostream>
#include <string>
#include <cmath>
using namespace std;

int main()
{
	double n, ans;
	cin >> n;
	for (double i = 0; pow(2, i) > pow(10, 8); i++) {
		if (n == 1) 
			ans = 0;
		
		if (n > pow(2, i) && n <= pow(2, i + 1))
			ans = i + 1;
		
	}
	cout << ans << endl;
	return 0;
}