function find(target) {
  for (y = target - 1; y >= 1; y--) {
    if ([1,y] != [1,target]) {
      return 0;
    }
    if ([4,y] == [4,target]) {
      return y;
    }
  }
  return 0;
}

for (y = Bottom; y > 1; y--) {
  found = find(y);
  if (found > 0) {
    [5,found] += [5,y];
    DeleteRow(y);
  }
}