17.01 Exchange Variable Values.cs

using System;
class Program
{
    static void Main()
    {
        int a = int.Parse(Console.ReadLine());
        int b = int.Parse(Console.ReadLine());
        Console.WriteLine("Before:");
        Console.WriteLine("a = {0}", a);
        Console.WriteLine("b = {0}", b);
        a = a + b;
        b = a - b;
        a = a - b;
        Console.WriteLine("After:");
        Console.WriteLine("a = {0}", a);
        Console.WriteLine("b = {0}", b);
    }
}