static int pos(int i)
{
return i % 3 == 0 ? 3 : i % 3;
}
static int[] a = null, x = null, y = null, z = null;
static void Main(string[] args)
{
a = new int[4];
x = new int[] { 0, 1, 2, 3 };
y = new int[] { 0, 4, 5, 6 };
for (int i = 1; i <= 3; i++)
{
int m = pos(i + 1), n = pos(i + 2);
a[i] = x[m] * y[n] - x[n] * y[m];
Console.WriteLine("a{0}=x{1}*y{2}-x{2}*y{1}t={3}*{4}-{5}*{6}t={7}", i, m, n, x[m], y[n], x[n], y[m], a[i]);
}
Console.ReadKey();
}