#include<bits/stdc++.h>
using namespace std;
bool judgement_prime_number(long long x)
{
	if(x<=1)return 0;
	for(long long i=2;i<sqrt(x);i++)
	{
		if(x%i==0)return 0;
	}
	return 1;
}
bool judgement_Palindromes(long long y)
{
	long long judgement=0;
	long long y2=y;
	while(y2!=0)
	{
		judgement=judgement*10+y2%10;
		y2/=10;
	}
	if(judgement==y)return 1;
	return 0;
}
bool Palindromes_AND_prime(long long x) 
{
	if(judgement_prime_number(x) && judgement_Palindromes(x))return 1;
	return 0;
}
int main()
{
	long long n,m;
	cin>>n>>m;
	for(long long i=n;i<=m;i++)
	{
		if(Palindromes_AND_prime(i))cout<<i<<endl;
	}
	return 0; 
}