#include<iostream>
#include<cmath>
#include<cstdio>
#include<algorithm>
#include<vector>
using namespace std;
int a[100005];
bool ss(int i)
{
	
	if(i<2) return 0;
	for (int j=2;j*j<=i;j++)
{if (i%j==0)
{return 0;}}
	return 1;
}
bool zss(int i)
{
	int t=0;
	if(ss(i))
	{
		while(i)
		{
			t=t*10+i%10;
			i/=10;
		}
		if (ss(t))
		return 1;
		else return 0;
	}
}
int main()
{
	int m,n;
	cin>>m>>n;
	int l=0;
	for(int i=m;i<=n;i++)
	{
		
		if(zss(i)&&l!=0) 
		{
			cout<<","<<i;l=1;
		}
		if(zss(i)&&l==0) 
		{
			cout<<i;l=1;
		}
	}
	if (l==0)
	cout<<"No";
	return 0;
	
	
}