java找规律解法

import java.util.*;

public class Main{
    public static void main(String [] args){
        Scanner sc = new Scanner(System.in);
        while(sc.hasNextInt()){
            int num = sc.nextInt();
            if(num == 1 || num == 2){
                System.out.println(-1);
            }else if(num % 4 == 0){
                System.out.println(3);
            }else if(num % 4 == 1 || num % 4 == 3){
                System.out.println(2);
            }else{
                System.out.println(4);
            }
        }
    }
}