题解 | #素数回文#

#include <iostream>
#include <cmath>
using namespace std;

bool ss(long long num){
    if(num < 2){
        return false;
    }
    
    for(long long i = 2; i <= sqrt(num); i++){
        if(num % i == 0){
            return false;
        }
    }
    
    return true;
}

int main() {
    long long  t;
    cin>>t;
    if(ss(t)){
        string t1 = to_string(t);
        string t2 = t1;
        for(int i=0;i<t1.length();i++){
            t2[i]=t1[t1.length()-2-i];
        }
        string tt = t1+t2;
        if(ss(stoll(tt))){
            cout<<"prime";
        }else{
            cout<<"noprime";
        }
        
    }
    
}