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

use Math::Combinatorics;
my @files;
push @files, "file$_" foreach (1..36);

my $c = Math::Combinatorics->new( count => 3, data => \@files);
while (my @combo = $c->next_combination()) {
	my %combins;
	@combins{@combo}=();
	my @leftovers = grep {!exists($combins{$_})} @files;
	print "Choose: @combo\tLeave: @leftovers\n";}