#include<bits/stdc++.h>
using namespace std;
bool falg;int s;
#define ii int
#define ll long long
//#define cc char
//#define dd double
//#define in cin
//#define out cout
//#define pp printf
//简化
bool sushu(int x){
	if(x<2){
		return false;
	}
	if(x==2||x==3){
		return true;//TODO
	}
	for(int i=2;i*i<=x;i++){
		if(x%i==0)return false;
	}return true;
}
// 素数*/
int d(int x){
	int a=0;
	while(x){
		a*=10,a+=x%10;//TODO
	}
	return a;
}
int main()
{	
	int m,n;cin>>m>>n;
	for(int i=m;i<=n;i++){
		if(sushu(i)&&sushu(d(i))){
			cout<<i;falg=true;s=i+1;//TODO
			
			
		}//TODO
	}
	for(int i=s;i<=n;i++){
		if(sushu(i)&&sushu(d(i))){
			cout<<','<<i;
		}//TODO
	}
	if(!falg){
		cout<<"No";//TODO
	}
	return 0;
}