sub beautify {
   my (%old, %new);
   return sort { $a <=> $b }
   grep {
          $new{$_}++;
          $old{$_}++ unless exists $old{$_};
          my $ret = $new{$_}==$old{$_} ?
                    1 :
                    $new{$_}+1==$old{$_} ? 1 : 0;
          $old{$_} = $new{$_};
          $ret;
       } @_;
}