function getMinPos(s, c1, c2) {
  p1 = pos(s, c1);
  p2 = pos(s, c2);
  if (p1 == 0) {
    return p2;
  }
  if (p2 == 0) {
    return p1;
  }
  return min(p1, p2);
}

for (y = 1; y <= Bottom; y++) {
  s = [1,y];
  for (x = 2; true; x++) {
    p = getMinPos(s, "（", "(");
    if (p == 0) {
      break;
    }
    s = mid(s, p + 1);

    p = getMinPos(s, "）", ")");
    if (p == 0) {
      break;
    }
    [x,y] = left(s, p - 1);
    s = mid(s, p + 1);
  }
}