{

  for (int c0 = 0; c0 < -(n % 8) + n; c0 += 8) {

    for (int c1 = 0; c1 < -(n % 8) + n; c1 += 8)

      for (int c2 = 0; c2 <= 7; c2 += 1)

        for (int c3 = 0; c3 <= 7; c3 += 1)

          A(c0 + c2, c1 + c3);

    for (int c2 = 0; c2 <= 7; c2 += 1)

      for (int c3 = 0; c3 < n % 8; c3 += 1)

        A(c0 + c2, -((n - 1) % 8) + n + c3 - 1);

  }

  for (int c1 = 0; c1 < n; c1 += 8)

    for (int c2 = 0; c2 < n % 8; c2 += 1)

      for (int c3 = 0; c3 <= min(7, n - c1 - 1); c3 += 1)

        A(-((n - 1) % 8) + n + c2 - 1, c1 + c3);

}