#include<iostream>
#include<stdlib.h>
#include<string.h>
using namespace std;
int c[10000],d[10000];
int main()
{
	long long a, b;
    int n, s = 0, m = 0, j, x = 0;
	cin >> a >> b;
	for (;a <= b;)
	{
		n = a;
		while (n)
		{
			s = s * 10 + n % 10;  
			n = n / 10;
		}
		if (s == a)
		{
			c[m] = a;
			m++;
		}
		a++;
		s = 0;
	}
	for (int i = 0;i < m;i++)
	{
		for (j = 2;j <= c[i];j++)
			if (c[i] % j == 0) break;
		if (j == c[i])
		{
			d[x] = j;
			x++;
		}
	}
	for (int i = 0;i < x;i++)
		cout << d[i] << endl;
	return 0;
}