#include <bits/stdc++.h>
using namespace std;
int n, m;
int wei(int x)
{
    if ((1000 <= x && x <= 9999) || (100000 <= x && x <= 999999))
    {
        return 0;
    }
    return 1;
}
int zhi(int x)
{
    int a[20], flag = 1;
    while (x > 0)
    {
        a[flag] = x % 10;
        x /= 10;
        flag++;
    }
    for (int i = 1; i <= flag / 2; i++)
    {
        if (a[i] != a[flag - i])
        {
            return 0;
        }
    }
    return 1;
}
int hui(int x)
{
    if (x == 2)
    {
        return 1;
    }
    for (int i = 2; i <= sqrt(x); i++)
    {
        if (x % i == 0)
        {
            return 0;
        }
    }
    return 1;
}
int main()
{
    cin >> n >> m;
    if (n == 2)
    {
        printf("2\n");
    }
    if (n % 2 == 0)
    {
        n++;
    }
    m = min(9999999, m);
    for (int i = n; i <= m; i += 2)
    {
        if (!wei(i) || !hui(i) || !zhi(i))
        {
            continue;
        }
        printf("%d\n", i);
    }
    
    return 0;
}