题解 | #素数回文#

import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        // 构造回文数
        String str = "" + n;
        StringBuilder sb = new StringBuilder();
        sb.append(str.substring(0, str.length()-1));
        String num = "" + n + sb.reverse().toString();
        long res = Long.parseLong(num);

        // 判断回文数是否是素数
        for (long i=2; i*i <= res; i++) {
            if (res % i == 0) {
                System.out.println("noprime");
                return;
            }
        }
        System.out.println("prime");
    }
}