#include <bits/stdc++.h>
using namespace std;
 
int main() {
	//Number of terms in the series having 0, 1.
	vector< long long > forward(2, 0), backward(2, 0);
	forward[1] = backward[1] = 1;
	long long MAX = 1e9;
	//Positive elements.
	while(forward.back() <= MAX){
		auto n = forward.size();
		auto next_element = forward[n-1] + forward[n-2];
		forward.push_back(next_element);
	}
	int count_elements = forward.size();
	//On the other side.
	while(abs(backward.back()) <= MAX){
		auto n = backward.size();
		auto next_element = backward[n-2] - backward[n-1];
		backward.push_back(next_element);
	}
	count_elements += backward.size() - 2;
	cout<<count_elements<<endl;
	return 0;
}

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