#include <iostream> #include <list> using namespace std; bool is_veg(int v) { for(int i = 2; i < v; i++) { if(!(v % i)) { return 0; } } return 1; } int main() { int m, n; cin >> m >> n; m = m % 2 ? m : m + 1; n = n % 2 ? n : n - 1; list<short> ls; bool b = 1; for(int i = m; i <= n; i += 2) { int temp = i; while(temp) { ls.push_back(temp % 10); temp /= 10; } for(list<short>::iterator i = ls.begin(); i != ls.end(); i++) { temp = temp * 10 + *i; } if(is_veg(i) && is_veg(temp)) { cout << i << " "; b = 0; } ls.clear(); } if(b) { cout << "No"; } cout << endl; return 0; }