#include <bits/stdc++.h> using namespace std; // 判断素数函数 bool isPrime(int n) { if (n < 2) return false; if (n == 2) return true; if (n % 2 == 0) return false; for (int i = 3; i * i <= n; i += 2) { if (n % i == 0) return false; } return true; } // 反转数字 int reverseNumber(int n) { int reversed = 0; while (n > 0) { reversed = reversed * 10 + n % 10; n /= 10; } return reversed; } int main() { int M, N; cin >> M >> N; vector<int> result; for (int num = M; num <= N; num++) { if (isPrime(num)) { int reversed = reverseNumber(num); if (isPrime(reversed)) { result.push_back(num); } } } // 输出结果 if (result.empty()) { cout << "No" << endl; } else { for (int i = 0; i < result.size(); i++) { cout << result[i]; if (i < result.size() - 1) { cout << ","; } } cout << endl; } return 0; }