#include <iostream>
using std::cout;
using std::cin;
using std::endl;

int main()
{
	int n;
	int prev = 1, curr = 1, next;
	bool found = false;

	cout << "Enter n: ";
	cin >> n;

	while(true)
	{
		next = prev + curr;

		if(found)
		{
			cout << next << endl;
			break;
		}

		if(next == n)
		{
			cout << curr << endl;
			found = true;
		}

		prev = curr;
		curr = next;
	}

	cin.get();
	return 0;
}