public static void Main()
Console.WriteLine("請輸入價格");
string price = Console.ReadLine();
int money = int.Parse(price);
sellprice = (money * 0.6);
Console.WriteLine($"折扣後價錢:{sellprice:C0}");
else if(money<=400 && money>300)
sellprice = (money * 0.7);
Console.WriteLine($"折扣後價錢:{sellprice:C0}");
else if (money<=300 && money>200)
sellprice = (money * 0.8);
Console.WriteLine($"折扣後價錢:{sellprice:C0},");
else if (money<=200 && money>300)
sellprice = (money * 0.9);
Console.WriteLine($"折扣後價錢:{sellprice:C0},");
Console.WriteLine($"原價:money:C0");