using System;

using System.Threading.Tasks;

public class Program

{

    public static void Main()

    {

        f();

        Console.WriteLine("From main thread");

        // vs

        f().Wait();

        Console.WriteLine("From main thread");

    }

    public static Task f()

    {

        return System.Threading.Tasks.Task.Run(() => { Console.WriteLine("From function"); });

    }

}