统计每个月兔子的总数

题目描述
有一只兔子，从出生后第3个月起每个月都生一只兔子，小兔子长到第三个月后每个月又生一只兔子，假如兔子都不死，问每个月的兔子总数为多少？

输入描述:
输入int型表示month

输出描述:

输出兔子总数int型

import java.util.Scanner;

public class Main
{
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNext())
        {
            int month = scanner.nextInt();
            System.out.println(count(month));
        }
    }
    public static int count(int month)
    {
        if (month == 1 || month == 2)
            return 1;
        return count(month - 1) + count(month - 2);
    }
}

import java.util.Scanner;

public class Main
{
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNext())
        {
            int month = scanner.nextInt();
            System.out.println(count(month));
        }
    }
    public static int count(int month)
    {
        if (month == 1 || month == 2)
            return 1;
       int old = 1;
       int young = 1;
       int month1 = 1;
       int month2 = 0;
       for (int i = 4; i <= month; i++)
       {
           old += month2;
           month2 = month1;
           month1 = old;
           young = month1 + month2;
       }
       return young + old;
    }
}