using System;
using System.Threading.Tasks;

public class Ex3
{
    public static async Task Run()
    {
        /* Example using a Task<T> type */
        var lowerCaseString = "i want to be an upper case string";
        Console.WriteLine("main: " + lowerCaseString);
        var upperCaseString = await WorkOnStringAsync(lowerCaseString);
        Console.WriteLine("main: " + upperCaseString);
    }

    private static async Task<string> WorkOnStringAsync(string s)
    {
        Console.WriteLine("Task: Async task started");
        Console.WriteLine("Task: Waiting for 2 sec");
        await Task.Delay(2000);
        Console.WriteLine("Task: Done waiting, returning the upper case string");
        return s.ToUpper();
    }
}