Problem C - 2 the 9s

Problem C - 2 the 9s.cs

using System;

namespace CPE
{
	class Program{
		public static void Main(string[] args){
			decimal value = decimal.Parse("999999999999999999999");
			Console.Write(Degree(value));
			Console.ReadKey(true);
		}
		
		
		static decimal Degree(decimal Value){
			decimal sum = Sum(Value);//位數值總和
			if(sum % 9 != 0)return 0;//如果不可以被整除則回傳0
			if(sum == 9)return 1;//如果剛好等於自己則可以執行一次
			return Degree(sum) + 1;//沒有除完則交給下一層計算
		}
		
		static decimal Sum(decimal Value){
			decimal sum = 0;
			for(; Value > 0;){
				sum += Value % 10;
				Value -= Value %10;
				Value /= 10;
			}
			return sum;
		}
	}
}