my @seen = ();
sub other {
	my $n = shift;
	my $a = 1;
	while ($seen[$a] || ($a & $n)!=0) {
		$a++;
	}
	$seen[$a]++;
	return $a;
}

foreach my $n (1..10_000) {
	my $a = other($n);
	print "$n $a\n";
}