Biggest Of 3 Integer Numbers

using System;
class BiggestOf3IntNums
{
  static void Main()
  {
    //Write a program that finds the biggest of three integers using nested if statements.

    Console.Write("Please enter the first integer number:");
    int firstNum = int.Parse(Console.ReadLine());
    Console.Write("Please enter the second integer number:");
    int secondNum = int.Parse(Console.ReadLine());
    Console.Write("Please enter the third integer number:");
    int thirdNum = int.Parse(Console.ReadLine());

    if (firstNum >= secondNum)
      if (firstNum >= thirdNum)
    {
      Console.WriteLine("The biggest number is {0}", firstNum);
    }
      else
      {
        Console.WriteLine("The biggest number is {0}", thirdNum);
      }
    else
    {
      if (secondNum >= thirdNum)
      {
        Console.WriteLine("The biggest number is {0}", secondNum);
      }
      else
      {
        Console.WriteLine("The biggest number is {0}", thirdNum);
      }
    }
  }
}