#include <iostream>
#include <vector>

std::vector<bool> seen(1);
size_t unseen = 0;

size_t other(size_t p) {
	seen[p] = true;
	while (unseen < seen.size() && seen[unseen]) {
		unseen++;
	}

	for (size_t v = unseen;; v++) {
		if (v == seen.size()) {
			seen.resize(2 * seen.size());
		}
		if (!seen[v]) {
			size_t pv = p & v;
			if (pv==0 || pv==p) {
				return v;
			}
		}
	}
}

int main() {
	size_t v = 0;
	for (size_t n = 0; n <= 10'000; n++) {
		std::cout << n << ' ' << v << std::endl;
		v = other(v);
	}

	return 0;
}