using namespace std;
int a,b,t[20001],pa1,pa[10000],y = 1;
int main(){
	cin>>a>>b;
	for(int i=a;i<=b;i++) 
	{
		pa1 = i;
		int pa2 = 0;
		while(pa1 > 0) 
		{
			pa2 = pa2 * 10 + pa1 % 10;
			pa1 /= 10;
			if(pa2 == i) 
			{
				t[y] = i;
				y++;
			}
		}
	}
	int z = 1;
	for(int i = 1;i <= 20000;i++) 
	{	int x = 2;
		while(x <= floor(sqrt(t[z])) && (t[z] % x != 0))x++;
		if(x > floor(sqrt(t[z])))
			cout<<t[z]<<'\n'; 
		z++;
	}
}