#!/usr/bin/perl -w

while($_ = <>) {
	@chr = $_=~/(.)/g;
	foreach $_ (@chr) {
		$c = ord $_;
		if ($_=~/[A-Ma-m]/) { $c = ($c + 13) }
		elsif ($_=~/[N-Zn-z]/) { $c = ($c - 13) }
		$_ = chr $c;
	}
	print ((join '',@chr) . "\n");
}