using System;

public class Program

{

    public void swap(int x, int y)

    {

        int temp;

        temp = x;

        x= y;

        y= temp;

    }

    public static void Main()

    {

        //Console.WriteLine("Hello World");

        Program p = new Program();

        int a = 100;

        int b = 200;

        Console.WriteLine("Before swap, value of a : {0}",a);

        Console.WriteLine("Before swap, value of b : {0}",b);

        p.swap(a,b);

        Console.WriteLine("After swap, value of a : {0}",a);

        Console.WriteLine("After swap, value of a : {0}",b);

        Console.ReadLine();

    }

}