#include<bits/stdc++.h>
using namespace std;
int main() {
	int a,b;
	vector<int> data={2,3,5,7,11,101,131,151,181,191,313,353,373,383,727,757,787,797,919,929,10301,10501,10601,11311,11411,12421,12721,12821,13331,13831,13931,14341,14741,15451,15551,16061,16361,16561,16661,17471,17971,18181,18481,19391,19891,19991,30103,30203,30403,30703,30803,31013,31513,32323,32423,33533,34543,34843,35053,35153,35353,35753,36263,36563,37273,37573,38083,38183,38783,39293,70207,70507,70607,71317,71917,72227,72727,73037,73237,73637,74047,74747,75557,76367,76667,77377,77477,77977,78487,78787,78887,79397,79697,79997,90709,91019,93139,93239,93739,94049,94349,94649,94849,94949,95959,96269,96469,96769,97379,97579,97879,98389,98689};
    cin>>a>>b;
    for(auto it=lower_bound(data.begin(),data.end(),a);it!=upper_bound(data.begin(), data.end(),b);++it) 
		cout<<*it<<endl;
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
bool zhishu(int n) 
{
	if (n<=1) 
		return false;
	for (int i=2;i<n;i++) 
	{
		if (n% i==0) 
			return false;
	}
	return true;
}//质数检测
bool huiwen(int n)
{
	int a,b;
	a=0;
	b=n;
	while(b>0)
	{
		a=a*10+b%10;
		b=b/10;
	}
	if(a==n)
		return true;
	else
		return false;
}//回文数检测
int main()
{
	int a,b,i,f,g,c;
	cin>>a>>b;
	for(i=a;i<=b;i++)
	{
		c=zhishu(i);
		if(c==1)//true
		{
			c=huiwen(i);
			if(c==1)
				cout<<i<<endl;
		}
	} 
	return 0;
}