#include <iostream>

using namespace std;

int main(void)
{
	int N;
	cin >> N;

	int count = 0;

	while(N != 1)
	{
		if (N % 2 != 1)
			N /= 2;
		else
			N = N / 2 + 1;

		count++;
	}

	cout << count << endl;

	return 0;
}