class Program     {         static void Main(string[] args)         {             //找规律：             //1,1,2,3,5,8,13,21,34,55,......             int num = 30;             Console.WriteLine(GetNum(30));             Console.ReadKey();         }         /// <summary>         /// 求第30位数的值         /// </summary>         /// <param name="i"></param>         /// <returns></returns>         private static int GetNum(int i)         {             if (i<=0)             {                 return 0;             }else if (i>0 && i<=2)             {                 return 1;             }             else             {                 return GetNum(i - 1) + GetNum(i - 2);             }         }     }