#include<iostream>
#include<cmath>
using namespace std;
int main()
{
    int m, n,h=1;
    cin >> m >> n;
    bool prime(int num); 
    int down(int num);
    for (int i = m; i <= n; i++)
    {
        if (prime(i) && prime(down(i)))
           { 
               cout << i << ",";
               h=0;
           }
    }
    cout << "\b";
    if(h)
        cout<<"No";
    return 0;
}
bool prime(int num) {
    if (num < 2) {
        return false;
    }
    for (int i = 2; i <= sqrt(num); i++) {
        if (num % i == 0) {
            return false;
        }
    }
    return true;
}
int down(int num)
{
	int reversed = 0;
    while (num != 0) {
        int digit = num % 10;
        reversed = reversed * 10 + digit;
        num /= 10;
    }
    return reversed;
}