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

(@ARGV == 2) or die "USAGE: $0 master complete\n";
my ($master, $complete) = @ARGV;

open(my $fh_complete, '<', $complete) or die "$complete: $!";
open(my $fh_master,   '<', $master  ) or die "$master: $!";

my %complete = map { $_=> 1 } <$fh_complete>;

my @incomplete = grep { !$complete{$_} } <$fh_master>;

print @incomplete;