for (int c0 = 0; c0 < floord(n + 1, 2); c0 += 1)
  for (int c1 = 0; c1 < (n + 1) / 2; c1 += 1) {
    if (n >= 2 * c1 + 2) {
      for (int c2 = 2 * c0 + 1; c2 <= min(n, 2 * c0 + 2); c2 += 1) {
        for (int c3 = 2 * c1 + 1; c3 <= 2 * c1 + 2; c3 += 1)
          (c0, c1, c2, c3);
        if (c0 == 0 && n >= c1 + 6 && c1 <= 1)
          for (int c3 = max(5, c1 + c2 + 3); c3 < n; c3 += 1)
            if ((c1 == 1 && (c3 % 3) + c2 >= 2 && c3 % 3 <= 1) || (c1 == 0 && (c3 + 1) % 3 == 0) || (c1 == 1 && c2 == 1 && c3 % 3 <= 1))
              (0, c1, c2, c3);
      }
      if (n >= 6 && c0 == 0 && c1 == 0) {
        for (int c2 = 3; c2 < n; c2 += 1)
          for (int c3 = 2; c3 < n; c3 += 1)
            if (2 * c3 >= c2 + 6 * floord(-c2 + 2 * c3 + 2, 6) + 2)
              (0, 0, c2, c3);
      } else if (n == 6 && c0 == 0 && c1 == 2) {
        (0, 2, 3, 4);
      }
    } else if (n >= 2 * c0 + 3) {
      for (int c2 = 2 * c0 + 1; c2 <= 2 * c0 + 2; c2 += 1)
        (c0, (n - 1) / 2, c2, n);
    }
    if (n <= 6 && c0 == 0 && c1 == 2) {
      for (int c2 = n - 2; c2 < n; c2 += 1) {
        if (n == 6) {
          (0, 2, c2, -2 * c2 + 12);
          if (c2 == 5)
            (0, 2, 5, 5);
        } else {
          (0, 2, c2, 3);
        }
      }
    } else if (c0 == 0 && c1 == 1) {
      for (int c2 = 3; c2 < n; c2 += 1) {
        if (n >= 6) {
          if (c2 == 3) {
            (0, 1, 3, 2);
            if (n >= 7)
              (0, 1, 3, 4);
          }
          for (int c3 = max(2, -3 * c2 + (c2 + 1) / 2 + 12); c3 < n; c3 += 1)
            if ((5 * c2 + 2 * c3 - 2) % 6 >= 4 || (2 * n >= ((5 * c2 + 2 * c3 - 2) % 6) + 11 && (5 * c2 + 2 * c3 - 2) % 6 >= 2))
              (0, 1, c2, c3);
        } else {
          (0, 1, c2, 2);
        }
      }
    }
    if (2 * c0 + 1 == n && 2 * c1 + 1 == n)
      ((n - 1) / 2, (n - 1) / 2, n, n);
  }