#include <bits/stdc++.h>
using namespace std;

int main()
{
int i;
int N;
int iCnt;

	cin >> N;

	i = 1;
	iCnt = 0;
	while( N > i )
	{
		i *= 2;
		iCnt++;
	}

	cout << iCnt << endl;

	return 0;
}