Easy

#include<bits/stdc++.h>
using namespace std;

bool PrimeTF(long long n)
{
	for(long long i=2;i*i<=n;i++)
	{
		if(n%i==0)return 0;
	}
	return 1;
}
bool HWTF(long long m)
{
	long long k=m,f=0;
	while(k)
	{
		f=f*10+k%10;
		k/=10;
	}
	if(f==m)return 1;
	return 0;
}
int main()
{
	long long a,b;
	cin>>a>>b;
	if(a%2==0)a++;
	for(int i=a;i<=b;i+=2)
	{
		if(HWTF(i)==1&& PrimeTF(i)==1)
		{
				cout<<i<<endl;
		}
		if(i>10000000)
		{
			return 0;
		}
	}
	return 0;
}