#include<bits/stdc++.h>
using namespace std;
long long a,b,g,n,h;
bool check(int  x)
{
	if(x <= 2) return false;
    if(x%2==0) return false;
    if((x!=11)&&(x%11==0)) return false;
	for(int i = 2; i <= sqrt(x); i++) 
		if(x % i == 0) return false;
	return true;
} 
bool hws(int  num) {
    int temp=num,ans=0;
    while (temp!=0) {
        ans=ans*10+temp%10;
        temp/=10;
    }
    if (ans==num)
        return true;
    else
        return false;
}
int main(){
	cin>>a>>b;
    if(a%2==0)a++;
	for(int i=a;i<=b;i+=2)
	{
        if(i>=9989900) break;
		if(check(i)&&  hws(i)) cout<<i<<endl;
	}
		
	return 0;
}

求调