if($l<$k){
  if($s_rev[$d+1]==0 && $k-2>0){
    $s_rev[$d+1] = $k-2;
  }
  $h=$s[$b] == 0 ? 0 : $s[$b]-1;
  $s[$b1] = max($k,$lt);
  $c=2;
  $j++;
}
elsif($l>$k){
  if($s[$b+1]==0 && $l-2>0){
    $s[$b+1] = $l-2;
  }
  $h=$s[$b] == 0 ? 0 : $s[$b]-1;
  $s[$b1] =max($l,$kt);
  $c=1;
  $i++;
}
else{
  if($s[$b+1]==0 && $k-2>0){
    $s[$b+1] = $k-2;
  }
  $s[$b1] = max($k,$lt);
  $h=0;
  $c=0;
}

sub max{

}