#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <math.h>


#define LL long long int
using namespace std;


int main(void)
{
	int n;
	cin >> n;
	int i = 0;
	int ans = 0;
	if (n == 1) {
		cout << ans<<endl;
		return 0;
	}

	while (n > ans) {
		i++;
		ans = pow(2, i);
	}

	cout << i << endl;
	return 0;
}