#include <iostream>
#include <fstream>
#include <vector>
std::ifstream fin("fractii.in");
std::ofstream fout("fractii.out");
std::vector<int> v;
int main()
{

	v.push_back(1);
	v.push_back(1);
	int member = 1;

	int n;
	fin >> n;
	int sol = 1;
	//fout << "1 / 1\n";
	for (int i = 1; i <= 1000000; ++i)
	{
		int a = v[member] + v[member - 1];
		v.push_back(a);
		v.push_back(v[member]);
		member++;
		if ((v[member] <= n) && (v[member - 1] <= n)) {
			//fout << v[member] << " / " << v[member - 1] << "\n";
			sol++;
		}
	}
	fout << sol << "\n";

	return 0;
}