java实现 统计每个月兔子的总数

import java.util.Scanner;

/**
 * 统计每个月兔子的总数
 */
public class Main{
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
         while(scanner.hasNext()){
            int mon= scanner.nextInt();
            System.out.println(getNum(mon));
        }
    }
    public static int getNum(int mon){
        if(mon == 1 ||mon == 2){
            return 1;
        }
        return getNum(mon-1)+getNum(mon-2);
    }
}