#include<iostream>
using namespace std;
bool isHws(int n);
int main()
{
	int d = 0;
	int p[1000000];
	bool f[10000000] = {0};
	f[0] = 1;
	f[1] = 1;
	int m,n;
	cin >> m>>n;
	for (int i = 2; i <= n; i++)
	{
		if (f[i] == 0)
			p[d++] = i;
		for (int j = 0; j < d; j++)
		{
			if (p[j] * i <= n)
				f[p[j] * i] = 1;
			else
				break;
			if (i % p[j] == 0)
				break;
		}
	}
	for (int i = 0; i < d; i++)
	{
		if(p[i]>=m&&p[i]<=n&&isHws(p[i]))
			cout<<p[i]<<endl;

	}
	return 0;
}
bool isHws(int num)
{
	int tem = num, ans = 0;
	while (tem != 0)
	{
		ans = ans * 10 + tem % 10;
		tem /= 10;
	}
	if (ans == num)
		return true;
	else return false;
}