兔子繁殖

import java.util.Scanner;
public class day1108 {
	public static void main(String[] args) {
		Scanner reader=new Scanner(System.in);
		System.out.print("过了几个月？");
		int m=reader.nextInt();
		int a=0,b=0,e,d,c=2,n=0;
		//3月龄：d
		//2月龄：b
		//1月龄：a
		//生产出：e
		do {
			e=c/2;
			d=b;
			b=a;
			a=e;
			c=c+d;
			n++;	
		}while(n<m);
		System.out.println("现在有兔子"+(a+b+c)+"只");
	}
}