using System;
using System.Threading;
class MainClass
{
public static void Main()
{
int firstInt = 25;
int secondInt = 80;
Console.WriteLine("firstInt initial value = {0}", firstInt);
Console.WriteLine("secondInt initial value = {0}", secondInt);
Interlocked.Exchange(ref secondInt, firstInt);
Console.WriteLine("firstInt after Exchange = {0}", firstInt);
Console.WriteLine("secondInt after Exchange = {0}", secondInt);
}
}