코드 한번 검토 부탁드립니다^^

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int num = scanner.nextInt();
        String [] arrStr = new String[num];
        for(int i =0;i<num;i++){
            arrStr[i] = scanner.next();
        }
        for(String s : arrStr){
            int ans = check(reverse(s));
            if(ans != 0){
                System.out.print(ans + " ");
            }

        }
    }
    public static int reverse(String str){
        str=new StringBuilder(str).reverse().toString();
        return Integer.valueOf(str);
    }
    public static int check(int num){
        if(num == 1) return 0;
        for (int i=2;i<num/2;i++){
            if(num%i == 0){
                return 0;
            }
        }
        return num;
    }
}