using System;

public class Program

{

    public static void Main()

    {

        const string Name = "Daniele";

        var helloer = new Helloer();

        helloer.SayHello(Name);

    }

}

​

//***********************************************************************//

public class Helloer

{

    public void SayHello(string name)

    {

        if (string.IsNullOrWhiteSpace(name))

        {

            Console.WriteLine("Empty name, can't say hello");

            return;

        }

        var greeting = GetGreeting(name);

        Console.WriteLine(greeting);

    }

    private string GetGreeting(string name)

    {

        return $"{DateTime.UtcNow} --> Hello {name}!";

    }

}

​

//******************************************************

// we have two lists l1 and l2

// write code to find the elements that belong to l1 and do not belong to l2

​

public class Foo {

    public List<int> AreInL1ButNotInL2 (List<int> l1, List<int> l2)

    {

    }

}

​