sub v{
  $m = pop;
  my @g = b\%t,$*;
  $s = \@g;
  $z = 0;
  map{ $x=0;
       map{
           $$s[$z][$x] = $$m[$z][$x] eq '#' && $$s[$z][$x] eq '#' ? '+' : '-';
           $x++
          } @$_;
       $z++
     } @$m;
  $s
}