#!/usr/bin/perl

sub rot13 {
  my ($string)=@_;
  $string=~tr/a-zA-Z/n-za-mN-ZA-M/;
  return $string;
}

my $new=" ";
my ($a,$b)=@ARGV;
if($a ne "-f"){
    $new="\n";
    $b=$a;
    }

my $c=&rot13($b);

print "$c$new";