如何在这种情况下为C＃使用do while循环？

static void Main()
{
  Console.WriteLine("Please Input the type of coffee you want! Your options are small, medium, or large!");

  double coffeeprice = 0;
  string coffeechoice = Console.ReadLine();

  switch (coffeechoice.ToUpper())
  {
    case "SMALL":
      coffeeprice += 2.00;
      break;
    case "MEDIUM":
      coffeeprice += 4.00;
      break;
    case "LARGE":
      coffeeprice += 6.00;
      break;

  }
  Console.WriteLine("Generating receipt for your {0} order now!", coffeechoice);
 }
}
static void Main()
{
  Console.WriteLine("Pleas