#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100000 + 5;
bool p[MAXN];

int lastPrime(int x){
	while (!p[--x]){}
	return x;
}

int reverse(int x){
	int a[15] = {};
	int cur = 0, res = 0;
	while (x){
		int g = x % 10;
		a[++cur] = g;
		x /= 10;
	}
	for (int i = 1;i <= cur;i++){
		res = res * 10 + a[i];
	}
	return res;
}

int main(){
    memset(p, true, sizeof(p));
    p[0] = p[1] = false;
    for (int i = 2;i <= MAXN;i++){
    	if (p[i]){
    		for (int j = 2;j <= MAXN / i;j++){
    			p[i * j] = false;
			}
		}
	}
	int n, m;
	scanf("%d", &n, &m);
	int last = lastPrime(m);
	for (int i = n;i <= m;i++){
		if (p[i] && p[reverse(i)]){
			printf("%d", i);
			if (i != last){
				printf(",");
			}
		}
	}
    return 0;
}