#include <bits/stdc++.h>
using namespace std;
int k;
int su(int k){
	if(k==1||k==0)return 0;
	if(k==2)return 1;
	for(int j=2;j*j<=k;j++)if(k%j==0)return 0;
	return 1;
}
int main(){
	stringstream ss;
	string s;
	int m,n;
	cin>>m>>n;
	for(int i=m;i<=n;i++){
		if(su(i)){
			s="";
			k=0;
			ss<<i;
			ss>>s;
			reverse(s.begin(), s.end());
			ss<<s;
			ss>>k;
			if(su(k))cout<<i<<","<<k<<",";
		}
	}
}