#!/usr/bin/perl

use strict;
use warnings;

use Data::Dumper;

my $to_encode = 'a perlhacker';
my $separator = '#';
my $set = [ map { chomp; [split /\s/, $_]; } <DATA> ];
my %keys; @keys{0..5} = qw/a d f g v x/;
my %lut;
for my $row (0 .. 5) {
   for my $col (0 .. 5) {
      $lut{$set->[$row]->[$col]} = $keys{$row}.$keys{$col};
   }
}
my $encoded =  join ' ', 
               map { $lut{$_} ? $lut{$_} : $separator } 
               split //, $to_encode;
               
print $encoded, "\n";

_ _DATA_ _
m l k 1 h g
p 2 o i f u
e r b d t z
5 6 s v 7 j
4 a q 3 c 9
y n 0 w 8 x