using System;

using System.Threading.Tasks;

public class Program

{

    public static async void Main()

    {

        var result = await Foo();

        Console.WriteLine(result);

    }

    private static async Task<int?> Foo()

    {

        return await TryCalc() ?? 1;

    }

    private static Task<int?> TryCalc()

    {

        return Task.FromResult<int?>(null);

    }       

}