using System;

public class Program

{

    public static void Main()

    {

        string fullname = "First M Last";

        Console.WriteLine("FullName: " + fullname);

        Console.WriteLine("FirstName: " + GetFirstName(fullname));

        Console.WriteLine("MiddleName: " + GetMiddleName(fullname));

        Console.WriteLine("LastName: " + GetLastName(fullname));

        Console.WriteLine("-------------------------------");

        fullname = "First Last";

        Console.WriteLine("FullName: " + fullname);

        Console.WriteLine("FirstName: " + GetFirstName(fullname));

        Console.WriteLine("MiddleName: " + GetMiddleName(fullname));

        Console.WriteLine("LastName: " + GetLastName(fullname));

        Console.WriteLine("-------------------------------");

        fullname = "First";

        Console.WriteLine("FullName: " + fullname);

        Console.WriteLine("FirstName: " + GetFirstName(fullname));

        Console.WriteLine("MiddleName: " + GetMiddleName(fullname));

        Console.WriteLine("LastName: " + GetLastName(fullname));

    }

    public static string GetFirstName(string FullName)

    {

        var nameParts = FullName.Split(new [] {' '}, StringSplitOptions.RemoveEmptyEntries);

​

        if (nameParts == null)

        {

            return null;

        }

        if (nameParts.Length > 0)

        {

            var firstName = nameParts[0];

            return firstName;

        }

        return null;

    }

    public static string GetMiddleName(string FullName)

    {

        var nameParts = FullName.Split(new [] {' '}, StringSplitOptions.RemoveEmptyEntries);

​

        if (nameParts == null)

        {

            return null;

        }

        if (nameParts.Length > 2)

        {

            var middleName = nameParts[1];

            return middleName;

        }

        return null;

    }

    public static string GetLastName(string FullName)

    {

        var nameParts = FullName.Split(new [] {' '}, StringSplitOptions.RemoveEmptyEntries);

​

        if (nameParts == null)

        {

            return null;

        }

        if (nameParts.Length > 2)

        {

            var lastName = nameParts[2];

            return lastName;

        }

        if (nameParts.Length > 1)

        {

            var lastName = nameParts[1];

            return lastName;

        }

        return null;

    }

}