using System;
using System.Timers;

internal class Program
{
    private static int counter = 0;
    private static string displayString = "This string will appear one letter at a time. ";

    private static void timeer(string[] args)
    {
        Timer myTimer = new Timer(30000.0);
        myTimer.Elapsed += new ElapsedEventHandler(Program.WriteChar);
        myTimer.Start();
        Console.ReadKey();
    }

    private static void WriteChar(object source, ElapsedEventArgs e)
    {
        Console.Write(displayString[counter++ % displayString.Length]);
    }
}