88分，最后一点超时了QAQ

#include<bits/stdc++.h>
using namespace std;
bool v[100000001];
void get_prime(int n){
    memset(v,true,sizeof(v));
    v[1] = false;
    int b = sqrt(n);
    for(int i=2;i<=b;i++){
        if(v[i]){
            for(int j=2;j<=n/i;j++) v[i*j] = false;
        }
    }
}
bool is_huiwen(int m){
    int t=m,ans = 0;
    while(t!=0){
        ans +=t%10;
        ans*=10;
        t/=10;
    }
    return m*10 == ans;
}
int main(){
    int a,b;
    cin>>a>>b;
    if(a>=100000000)a=9999999;
    get_prime(b);
    if(a>b) return 0;
    if(a%2==0) a++;
    for(int j=a;j<=b;j+=2){
        if(v[j]&&is_huiwen(j)) cout<<j<<endl;
    }
    return 0;
}