#!/usr/bin/perl

# caesar.pl

# usage, to shift the phrase "THE SECRET WORD IS PASTA" by 13:

# echo "THE SECRET WORD IS PASTA" | caesar.pl 13

$key = $ARGV[0];

$plaintext = <STDIN>;

$plaintext =~ s/\s+//g;

@chars = split('',$plaintext);

for $c (@chars) {
    print chr((ord($c)-ord("A")+$key)%26+ord("A"));
}

print "\n";