$mutus = "MUSTCODEINPERLIGATA";
@nomen = (0,1,3,1,2,6,7,6,8,3,9,5,0,7,9,4,5,4,8,2);
$count =0;
foreach $index(@nomen) {
    print substr($mutus,$index,1);
    unless (++$var %5) {
         print "\n";
    }
}