#include <bits/stdc++.h>
using namespace std;
long long zs(long long x) {
	if(x == 1)
		return 0;
	if(x == 2)
		return 1;
	for (long long i = 2; i < x; i++)
		if(x % i == 0) 
			return 0;
	return 1;
}
int main() {
	long long s, m, n, a, b;
	scanf("%lld%lld", &m, &n);
	for (s = m; s <= n; s++) {
		a = s / 100;
		b = s / 10;
		if(zs(s) == 1 && zs(a) == 1 && zs(b) == 1)
			printf("%lld\n", s);
	} 
	return 0; 
}