base = 10

print ("0 0");

a = vector(base^logint(10 000, base))
u = 1

{
	for (v=1, oo,
		d = digits(v, base);
		w = v;
		for (f=1, #d,
			if (d[f],
				for (t=f, oo,
					if (t>#d,
						d=concat(d, digits(w++, base));
					);
					m=fromdigits(d[f..t], base);
					if (m>#a,
							break,
						!a[m],
							a[m]=v;
					);
				);
			);
		);

		while (a[u],
			print (u " " a[u]);
			if (u++>#a,
				break (2);
			);
		);
	);
}

quit