use strict;
use warnings;

my $M = 5;
my @a = 1..$M;
my $N =  3;

get_all_tuples ($N, [], @a);

sub get_all_tuples {
	my ($level, $valref, @a) = @_;
	if ($level <= 1) {
		print "@$valref $_\n" for @a;
	} else {
		while (@a) {
			my $i = shift @a;
			push @$valref, $i;
			get_all_tuples ($level-1, $valref, @a);
			pop @$valref;
		}
	}
}