#include<iostream>
#include<stdio.h>
#include<math.h>
#include<iomanip>
#include<string>
#include<algorithm>
using namespace std;


int main()
{
	int m, n;
	cin >> m >> n;
	int p, q,k,count=0;
	string s;
	for (int i = m; i <= n; i++)
	{	
		p = 0;
		q = 0;
		for (int j = 2; j < i; j++)
		{
			if (i % j == 0)
			{
				break;
			}
			if (j == i - 1)
			{
				p = 1;
			}
		}
		s = to_string(i);
		reverse(s.begin(), s.end());
		k = atoi(s.c_str());
		for (int j = 2; j < k; j++)
		{
			if (k % j == 0)
			{
				break;
			}
			if (j == k - 1)
			{
				q = 1;
			}
		}
		if (p == 1 && q == 1)
		{
			count++;
		}
	}
	if (count == 0)
	{
		cout << "No";
		return 0;
	}
	//
	for (int i = m; i <= n; i++)
	{
		p = 0;
		q = 0;
		for (int j = 2; j < i; j++)
		{
			if (i % j == 0)
			{
				break;
			}
			if (j == i - 1)
			{
				p = 1;
			}
		}
		s = to_string(i);
		reverse(s.begin(), s.end());
		k = atoi(s.c_str());


		for (int j = 2; j < k; j++)
		{
			if (k % j == 0)
			{
				break;
			}
			if (j == k - 1)
			{
				q = 1;
			}
		}
		if (p == 1 && q == 1)
		{
			if (count != 1)
			{
				cout << i << ",";
				count--;
			}
			else
				cout << i;
		}
	}
	return 0;
}