for (my $i=0; $i<@numbers; $i++)      {

   # psudocode # 

   # if $numbers[$i] matches a value in @needed;  
   # push @found, all the numbers until the next match

           for (my $k = 0; $k < @needed; $k++)   {


                 if ($numbers[$i] ==  $needed[$k])   {

                       push @found, $numbers[$i];  

    # not sure how to carry on until the next match! 
                 }

          }

   }


}