{

  for (int c1 = 0; c1 <= 7; c1 += 1)

    S1(1, c1);

  for (int c0 = 2; c0 <= 6; c0 += 1) {

    for (int c1 = 0; c1 < c0 - 1; c1 += 1)

      S2(c0, c1);

    for (int c1 = c0 - 1; c1 <= 4; c1 += 1) {

      S1(c0, c1);

      S2(c0, c1);

    }

    for (int c1 = 5; c1 <= 7; c1 += 1)

      S1(c0, c1);

  }

  for (int c0 = 7; c0 <= 8; c0 += 1)

    for (int c1 = c0 - 1; c1 <= 7; c1 += 1)

      S1(c0, c1);

}