using System;

using System.Threading.Tasks;

​

public class Program

{

    public static Random r = new Random();

    public static void Main()

    {

        ChangePassword().Wait();

    }

​

    public static async Task ChangePassword()

    {

        var success = false;

        while (!success)

        {

            try

            {

                var result = await AddPasswordAsync();

                success = true;

                Console.WriteLine(result);

            }

            catch (Exception)

            {

                Console.WriteLine("Error");

            }

        }

    }

​

    public static async Task<string> AddPasswordAsync()

    {

        // mimic a random number of failure attempts.

        await Task.Delay(10);

        if (r.Next(0, 10) != 5)

        {

            throw new Exception();

        }

​

        return "NewPassword";

    }

}