#!/usr/bin/perl 

eval 'exec /usr/bin/perl  -S $0 ${1+"$@"}'
    if 0; # not running under some shell

use strict;
use List::Vectorize;

open F1, $ARGV[0] or die "cannot open $ARGV[0]";
open F2, $ARGV[1] or die "cannot open $ARGV[1]";
print join "", @{setdiff([ <F1> ], [ <F2> ])};
