inline int gcd( int A, int B, int &X, int &Y )
{
	if (B == 0)
	{
		X = 1;
		Y = 0;
		return A;
	}

	int X0, Y0, D;
	D = gcd( B, A % B, X0, Y0 );
	
	X = Y0;
	Y = X0 - (A / B) * Y0;
	return D;
}

