#include <stdio.h>

int is_prime(int i) {
    for (int n = 2; n * n <= i; n++) {
        if (i % n == 0) {
            return 0;
        }
    }
    return 1;
}

int is_palindrome(int i) {
    int reverse = 0;
    int n = i;
    while (i > 0) {
        int left = i % 10;
        reverse = reverse * 10 + left;
        i /= 10;
    }
    return (n == reverse);
}

int is_number(int i) {
    return (is_prime(i) && is_palindrome(i));
}

int main() {
    int a=0;
    int b=0;
    scanf("%d%d",&a,&b);
    for (int i = a; i <= b; i++) {
        if (is_number(i)) {
            printf("%d\n", i);
        }
    }
    return 0;
}