#include <bits/stdc++.h>
using namespace std;
int hwspd(int hws);
int zspd(int zs);
int main(){
	int a,b;
	cin>>a>>b;
	if(a%2==0)
		a++;
	for(int i=a;i<=b;i+=2)
		if(hwspd(i)==1&&zspd(i)==1)
			cout<<i<<endl;
	return 0;
}

int hwspd(int hws){
	string ch,hc;
	while(hws>0){
		int c=hws%10;
		ch+=c+'0';
		hws/=10;
	}	
	for(int i=ch.size()-1;i>=0;i--)
		hc+=ch[i];
	if(ch==hc)
		return 1;
}

int zspd(int zs){
	int sum=0;
	for(int i=2;i<=zs-1;i++)
		if(zs%i!=0)
			sum++;
	if(sum==zs-2)
		return 1;
}