using System;

public class Program

{

    public static void Main()

    {

        var val1 = new TimeSpan(0, 0, 3);

        var val2 = new TimeSpan(0, 0, -5);

        TimeSpan? val2Nullable = null;

        val2Nullable = val2;

        var SumCoalescing = val2Nullable ?? TimeSpan.Zero + val1;

        var SumImplicit = val2Nullable.Value + val1;

        Console.WriteLine("val1           " + val1.ToString());

        Console.WriteLine("val2          " + val2.ToString());

        Console.WriteLine("val2Nullable  " + (val2Nullable ?? TimeSpan.Zero).ToString());

        Console.WriteLine("SumCoalescing " + SumCoalescing.ToString());

        Console.WriteLine("SumImplicit   " + SumImplicit.ToString());

    }

}