#include<bits/stdc++.h>
using namespace std;
bool p[100000005];
int prime[5761460];
int cnt=0; 
bool re_num(int x){
	int res=x,tmp=0;
	while(res)tmp=tmp*10+res%10,res/=10;
	return tmp==x;
}
inline int read(){
   int s=0,w=1;
   char ch=getchar();
   while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
   while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
   return s*w;
}
inline void write(int num){
	if(num<0){putchar('-');write(-num);}
	else if(num>=10){write(num/10);putchar(num%10+'0');}
	else if(num<10)putchar(num+'0');
	return;
}
int main(){
	memset(p,1,sizeof(p));
	int a,b;
	a=read(),b=read();
	for(int i=2;i<=b;i++){
		if(p[i]){
			cnt++;
			prime[cnt]=i;
			for(int j=i+i;j<=b;j+=i)p[j]=0;
		}
	}
	for(int i=1;i<=cnt;i++)if(re_num(prime[i])&prime[i]>=a){
		write(prime[i]);
		putchar('\n');
	}
	return 0;
}

RT