#!/usr/bin/perl
use warnings;
use strict;

open( my $out_fh, ">", "output.txt" ) || die "Can't open the output file for wri
ting: $!";

open( my $address_fh, "<", "Address.txt" ) || die "Can't open the address file:
$!";
my %lookup = map { chomp; split( /,/, $_, 2 ) } <$address_fh>;

open( my $file_fh, "<", "File.txt" ) || die "Can't open the file.txt file: $!";
while (<$file_fh>) {
    my @line = split;
    for my $char ( @line ) {
        ( exists $lookup{$char} ) ? print $out_fh " $lookup{$char} " : print $ou
t_fh " $char ";
    }
    print $out_fh "\n";
}