题目：求在 $n$ 到 $m$ 之间的回文质数。

#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll n,m;
ll read(){
	char ch=getchar();
	ll s=0,w=1;
	while(ch<'0' or ch>'9'){
		if(ch=='-')w=-1;
		ch=getchar();
	}while(ch>='0' and ch<='9'){
		s=s*10+ch-'0';
		ch=getchar();
	}return s*w;
}
bool zs(ll x){
	if(x==2) return true;
	if(x<2 or x%2==0) return false;
	for(ll i=3;i<=sqrt(x);i+=2)if(x%i==0) return false;
	return true;
}
bool hws(ll x){
	ll s=0,k=x;
	while(x!=0){
		s=s*10+x%10;
		x/=10;
	}if(s==k) return true;
	return false;
}
int main(){
	n=read(),m=read();
	for(ll i=n;i<=m;i++){
		if(i>9989899) break;
		if(hws(i) and zs(i)) 
		cout<<i<<endl;
	}return 0;
}