#include <bits/stdc++.h>
#include <vector>
using namespace std;
bool ifnum(int n){
	if(n==1)return 0;
	if(n==2)return 1;
	if(n%2==0)return 0;
	for(int i=3;i*i<=n;i++){
		if(n%i==0) return 0;
	}
	return 1;
}
int main(){
	long long a,b;
	bool f=false,o;
	cin>>a>>b;
	for(int i=a;i<=b;i++){
		string e=to_string(i);
		reverse(e.begin(),e.end());
		int a1=stoi(e);
		if(ifnum(i)&&ifnum(a1)){
			if(f){
				cout<<",";
			}
			cout<<i;
			f=1;
			o=1;
		}
	}
	if(!o){
		cout<<"No";
	}
	return 0;
}

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