Sort Descending 3 Real Values

using System;
class SortDescending3RealValues
{
  static void Main()
  {
    //Sort 3 real values in descending order using nested if statements.

    Console.Write("Please enter the first real number:");
    decimal firstNum = decimal.Parse(Console.ReadLine());
    Console.Write("Please enter the second real number:");
    decimal secondNum = decimal.Parse(Console.ReadLine());
    Console.Write("Please enter the third real number:");
    decimal thirdNum = decimal.Parse(Console.ReadLine());
    decimal listNum1, listNum2, listNum3;

    if (firstNum >= secondNum)
      if (firstNum >= thirdNum)
        if (secondNum >= thirdNum)
        {
          listNum1 = firstNum;
          listNum2 = secondNum;
          listNum3 = thirdNum;
        }
        else
      {
        listNum1 = firstNum;
        listNum2 = thirdNum;
        listNum3 = secondNum;
      }
      else
      {
        listNum1 = thirdNum;
        listNum2 = firstNum;
        listNum3 = secondNum;
      }
    else
    {
      if (secondNum >= thirdNum)
      {
        listNum1 = secondNum;
        listNum2 = thirdNum;
        listNum3 = firstNum;
      }
      else
      {
        listNum1 = thirdNum;
        listNum2 = secondNum;
        listNum3 = firstNum;
      }
    }
    Console.WriteLine("The entered numbers are:\n {0}\n {1}\n {2}\n", firstNum, secondNum, thirdNum);
    Console.WriteLine("In descending order they look like this:\n {0}\n {1}\n {2}\n", listNum1, listNum2, listNum3);
  }
}