using System;

public class Program

{

    public static void Swap<T>(ref T a, ref T b)

    {

        T temp;

        temp = a;

        a = b ;

        b = temp;

    }

    public static void Main()

    {

        int a =  10,b = 30;

        Swap<int>(ref a, ref b);

        Console.WriteLine(a + "---------" + b);

    }

}