using System;

public class Program

{

    public static void Main()

    {

        Kottan lisa = new Kottan("Lisa");

        Kottan jack = new Kottan("Jack");

        var kitten = jack + lisa;

        Console.WriteLine(kitten);

    }

}

​

public class Kottan

{

    private readonly string name;

    private readonly string middleName;

    public static Kottan operator + (Kottan maleCat, Kottan womanCat)

    {

        return new Kottan(NameHelper.Random(), maleCat.Name + "ovich");

    }

    public Kottan(string name, string middleName = "Ivanovna")

    {

        this.name = name;

        this.middleName = middleName;

    }

    public string Name

    {

        get { return name; }

    }

    public string MiddleName

    {

        get { return middleName; }

    }

    public override string ToString()

    {

        return string.Format("Name: {0}, MiddleName: {1}", name, middleName);

    }

}

​

public class NameHelper

{

    public static string Random()

    {

        return "Tom";

    }

}