题解 | #杨辉三角的变形#

q53

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