#include<bits/stdc++.h> using namespace std; bool is(int a){ if(a == 1){ return false; } for(int j = 2;j <= sqrt(a);j++){ if(a%j == 0){ return false; } } return true; } int fx(int a){ int m = 0; while(a>0){ m = m*10+a%10; a= a/10; } return m; } int main(){ int m,n,k,flag = 0; cin >> m >> n; for(int i = m;i <= n;i++){ k = fx(i); if(is(i) && is(k)){ if(flag == 0){ cout << i; flag = 1; }else{ cout<< "," << i; } } } if(flag == 0){ cout << "No"; } return 0; }