#include <iostream> using namespace std; int n,m; bool is_prime(int x) { if (x < 2) { return false; } for (int i = 2;i * i <= x;i++) { if (x % i == 0) { return false; } } return true; } int fan_shu(int x) { int r = 0; while (true) { int g = x % 10; r = r * 10 + g; x /= 10; if (x == 0) { return r; } } } int main() { cin>>m>>n; int cnt = 0; for (int i = m;i <= n;i++) { if (is_prime(i) && is_prime(fan_shu(i))) { cnt++; if (cnt==1) { cout<<i; }else { cout<<","<<i; } } } if (cnt==0) { cout<<"No"; } return 0; }