#include <bits/stdc++.h>
using namespace std;
struct CWW{CWW(){ios::sync_with_stdio(false);cin.tie(0);}}cww;
int main()
{
	int N;
	cin >> N;
	int total{1},res{};
	bool flag = false;
	while( true )
	{
		if( total*2 <= N )
		{
			total = total*2;
			res++;
		}
		else if( total*2 > N )
		{
			total += 1;
			flag = true;
		}
		if( total == N ){ break; }
	}
	cout << ( flag ? res + 1 : res ) << endl;
	return 0;
}