Exchange Two Integer Numbers If the First Is Bigger

using System;
class ExchangeTwoIntNumsIfFirstIsBigger
{
  static void Main()
  {
//Telerik Academy
    //Write an if statement that examines two integer variables and exchanges their values if the first one is greater than the second one.

    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());

    if (firstNum == secondNum)
    {
      Console.WriteLine("The first number is equal to the second one! {0} = {1}", firstNum, secondNum);
    }
    else if (firstNum < secondNum)
    {
      Console.WriteLine("The first number is smaller than the second one! {0} < {1}", firstNum, secondNum);
    }
    else if (firstNum > secondNum)
    {
      Console.WriteLine("The first number is bigger than the second one! {0} > {1}", firstNum, secondNum);
      firstNum += secondNum;
      secondNum = firstNum - secondNum;
      firstNum -= secondNum;
      Console.WriteLine("The first number is now equal to {0} and the second number is equal to {1}!", firstNum, secondNum);
    }
  }
}