PI Works Technical Questionnaire - SW Support

namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("The value of the 1st variable: ");//request the first number from the command screen
            int a =Int32.Parse(Console.ReadLine());//takes the first number entered
            Console.Write("The value of the 2nd variable: ");//request the second number from the command screen
            int b= Int32.Parse(Console.ReadLine());//takes the second number entered
            a = a + b;//sum the number of a and the number b
            b = a - b;//subtract the number b from the total and find the first number  a and save it to b
            a = a - b;//subtract the number b from the total and find the first number b and save it to a
            Console.WriteLine("---------------------------------------");//spacing
            Console.WriteLine("The value of the 1st variable: "+a);//write the Changing the number a
            Console.WriteLine("The value of the 2st variable: "+b);//write the Changing the number b
            Console.Write("Press a key to close the application");// to show the result of the program on console
            Console.ReadKey();//after presiing a key close the program
        }
    }
}