#include <iostream>
using namespace std;
bool legal(int m, int k)
{
	int i, a = 0;
	bool legal1 = true;
	for (i = 1; i <= k; i++)
	{
		int temp = (a + m - 1) % (2 * k + 1 - i);
		if (temp < k || temp > 2 * k - i){
			legal1 = false; 
			break;
		}
		a = temp;
	}
	return legal1;
}
int main(int argc, char* argv[])
{
	int k;
	while (cin >> k)
	{
		if(k == 0) return 0;
		int m1, m2; 
		for(m1 = 0, m2 = 1 ; !legal(m1, k) && !legal(m2, k); m1 += (k+1), m2 += (k+1));
		{
			if(legal(m1, k)) cout << m1 << endl; 
			else if(legal(m2, k)) cout << m2 << endl; 
		}		
	}
	return 0;
}