using System.Threading;
using System;
public delegate int BinaryOp(int x, int y);
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Main() invoked on thread {0}.",Thread.CurrentThread.ManagedThreadId);
BinaryOp b = new BinaryOp(Add);
int answer = b(10, 10);
Console.WriteLine("Doing more work in Main()!");
Console.WriteLine("10 + 10 is {0}.", answer);
Console.ReadLine();
}
static int Add(int x, int y)
{
Console.WriteLine("Add() invoked on thread {0}.",Thread.CurrentThread.ManagedThreadId);
Thread.Sleep(5000);
return x + y;
}
}