#include<iostream>
using namespace std;
int main() {
	int N, Biscuit = 1, Pocket = 1, count = 0;
	cin >> N;
	while (Biscuit != N) {
		if (Biscuit + Pocket <= N) {
			Biscuit = Pocket + Biscuit;
			Pocket = Biscuit;
			count++;
			//cout << Biscuit << endl;
		}
		else {
			Pocket = (N - Biscuit);
			if (Pocket == 0)Pocket = 1;
		}
	}
	//cout << Biscuit << endl;
	cout << count << endl;
}