#include<iostream>
#include<string>
#include<fstream>
#include<iomanip>
#include<vector>
#include<cctype>
#include<algorithm>
#include<sstream>
using namespace std;

int main()
{
	long long a = 1, n, cnt = 0;
	cin >> n;
	while (a < n)
	{
		cnt++;
		a *= 2;
	}
	cout << cnt << endl;
	return 0;
}