using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var list = new List<TimeSpan?>();

        list.Add(null);

        list.Add(TimeSpan.FromHours(1));

        Console.WriteLine(list.Min());  

        var list2 = new List<TimeSpan?>();

        Console.WriteLine(list2.Min()); 

    }

}