$| = 1;

my $champ = "";
my $unseen = 2;

sub a {
	my $n = shift;
	my $bin = sprintf("%b", $n);

	while (1) {
		my $pos = index($champ, $bin);
		if ($pos >= 0) {
			return $pos;
		} else {
			$champ .= substr(sprintf("%b", $unseen), 1);
			$unseen++;
		}
	}
}

foreach my $n (0..2**14) {
	my $a = a($n);
	print "$n $a\n";
}