#include <iostream>
#include <vector>
using namespace std;
int num_of_1(int n)
{
	int count = 0;
	while (n)
	{
		if (n % 10 == 1)
			count++;
		n /= 10;
	}
	return count;
}
//0,1,1,2,3,5,8,13,21,34...
int main()
{
	int n;
	while (cin >> n)
	{
		if (n == 1)
		{
			cout << 0 << endl;
		}

		else if (n == 2)
		{
			cout << 1 << endl;
		}
		else
		{
			vector<int>f(n + 1, 0);
			f[1] = 0;
			f[2] = 1;
			for (int i = 3; i <= n; i++)
			{
				f[i] = f[i - 1] + f[i - 2];
			}
			int res = 0;
			for (int i = 1; i <= n; i++)
			{
				res += num_of_1(f[i]);
			}
			cout << res << endl;
		}
	}



	system("pause");
	return 0;
}