man bedim len?

$a=r(999999998);
$b=(r(50)+32)*10000+r(11)*100+r(27);
$c=(r(5)+2)*10000+r(11)*100+r(27);
printf("%09d%01dD << %06d%01d < %06d%01d <<<<<< %01d\n",
   $a, c($a), $b, c($b), $c, 
   c($c), 
   (c($a)*8
        +c($b*100+c($b)*10)
        +c($c*10+c($c)))
    %10);

sub r{
   1+int(rand($_[0]));
}
sub c{
  $x=shift;
  $t=0;
  $s=1;
  while($x){
      $t+= ($x%10)*$s;
      $x=int($x/10);
      $s=$s<6?(1+($s*2)):1
  }
  $t%10
}
#-----------FNORD