s = 0
unseen = 1
seen(v) = bittest(s, v)
see(v) = s = bitor(s, 2^v); while (seen(unseen), unseen++)

base = 10
cat(x,y) = x*base^#digits(y,base) + y

{
	for (n=unseen, 10 000,
		for (v=unseen, oo,
			if (!seen(v),
				if (isprime(p=cat(n,v)) || isprime(p=cat(v,n)),
					see(v);
					print (n " " v);
					break;
				);
			);
		);
	);
}

quit