using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Day015
{
class Program
{
public class FibClass
{
public int Fib(int x)
{
if (x<3)
{
return 1;
}
else
{
return Fib(x - 2) + Fib(x - 1); //回调函数(方法)
}
}
}
static void Main(string[] args)
{
int x = int.Parse( Console.ReadLine()); //从键盘输入一个数字
FibClass fib = new FibClass(); //实例化方法
Console.WriteLine(fib.Fib(x));
Console.ReadKey();
}
}
}