using System;

public class Program

{

    public static void Main()

    {

        var maxLong = ulong.MaxValue;

        ulong messagesPerSec = 500;

        var secsPerMin = 60;

        var minPerHour = 60;

        var hoursPerDay = 24;

        var daysPerYear = 365;

        ulong secsPerYear = (ulong)(secsPerMin * minPerHour * hoursPerDay * daysPerYear);

        var yearsWeAreSafe = maxLong / messagesPerSec / secsPerYear;

        Console.WriteLine(yearsWeAreSafe);

    }

}