include<iostream>

include<cmath>

using namespace std; bool isPalindrome(int num) { long long reversedNum = 0, originalNum = num; while (num > 0) { reversedNum = reversedNum * 10 + num % 10; num /= 10; } return originalNum == reversedNum; } bool isPrime(int n) { if (n <= 1) return false; if (n == 2 || n == 3) return true; if (n % 2 == 0) return false; for (int i = 3; i <= sqrt(n); i += 2) { if (n % i == 0) return false; } return true; } int main() { int a, b; cin >> a >> b;
if (a < 5) a = 5; if (b > 100000000) b = 100000000;

for (int i = a; i <= b; i++) {
    if (isPrime(i) && isPalindrome(i)) {
        cout << i << endl;
    }
}

return 0;

}