using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        Console.WriteLine($"Nächster Feierabend in {GetNextFeierAbend()} Sekunden");

    }

    public static int GetNextFeierAbend()

    {

        return Enumerable.Range(0,7)

            .Select(n => DateTime.Today.AddDays(n))

            .Where(d => d.DayOfWeek != DayOfWeek.Saturday

                   && d.DayOfWeek != DayOfWeek.Sunday)

            .Select(d => d.DayOfWeek == DayOfWeek.Friday ? d.AddHours(16) : d.AddHours(17))

            .Select(d=> d-DateTime.Now.AddHours(1)) // zeitzonendifferenz

            .Select(d => (int)d.TotalSeconds)

            .Where(d => d>=0)

            .Min();

    }

}