void quickSort(int l, int r)
{
    int x = rty[l + (r - l) / 2];
    int i = l;
    int j = r;
    while(i <= j)
    {
        while(rty[i] < x) i++;
        while(rty[j] > x) j--;
        if(i <= j)
        {
            swap(rty[i], rty[j]);
            i++;
            j--;
        }
    }
    if (i<r)
        quickSort(i, r);

    if (l<j)
        quickSort(l, j);
}