#include <iostream>

#include <math.h>

#include <string>

#include <algorithm>

#include <sstream>

using namespace std;

bool isPrime(int n)

{

	for (int i = 2; i <=sqrt(n); i++)

	{

		if (n%i == 0)

		{

			return false;

		}

	}

	return true;

}

int Reverse(int n)

{

	std::string temp;

	std::stringstream ss;

	ss << n;

	ss >> temp;

	reverse(temp.begin(), temp.end());

	int t = atoi(temp.c_str());

	return t;

}

int main()

{

	int M, N;

	cin >> M >> N;

	std::string c;

	for (int i = M; i <= N; i++)

	{

		if (isPrime(i) && isPrime(Reverse(i)))

		{

			stringstream ss;

			string temp;

			ss << i;

			ss >> temp;

			c=c+temp+",";

		}

	}

	if (c.size()<1)

	{

		std::cout << "No";

	}

	else

	{

		for (int i = 0; i < c.size()-1;i++)

		{

			std::cout << c[i];

		}

	}

	//system("pause");

	return 0;

}