#include <iostream>
#include <stdio.h>
#include <bitset>
#include <time.h>

using namespace std;

const int maxn = 1e8;
bitset<maxn> pri;
int primes[maxn], palind[maxn], result[maxn], pp = 0, k = 0;

void PalindPrimes(int result[], int primes[], int b){
	for(int i = 2; i <= b; i++){
		if(!pri[i])	{
			primes[++pp] = i;	//素数
			int t = primes[pp];
			int m = 0;
			while(t > 0){
				int temp = t % 10;
				m = m * 10 + temp;
				t /= 10;
			}
			if(m == primes[pp]) result[k++] = m; //此素数是否回文 			
		}
		for(int j = 1; j <= pp && i * primes[j] <= b; j++){
			pri[primes[j] * i] = 1;
			if(i % primes[j] == 0)	break;
		}
	}
}



int main()
{
	int a,b;
 	scanf("%d%d", &a,&b);
	PalindPrimes(result, primes, b); 	//生成从2到b的所有素数
	
	int i = -1;
	while(result[++i] < a);
	
	int j = -1;
	while(result[++j] < b) if(result[j] == 0) break;
	
	for(i; i < j; i++) 
	{
		cout << result[i] << "\n";
	} 
	
	
	
	return 0; 
}