using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public class House

    {

        public string Address { get; set; }

        public List<Person> Housemates { get; set; }

    }

    public class Person

    {

        public string Name { get; set; }

        public string Surname { get; set; }

        public List<string> Phones { get; private set; }

​

        public Person()

        {

            Phones = new List<string>();

        }

    }

    public static void Main()

    {

        var person1 = new Person { Name = "Adam", Surname = "Smith" };

        person1.Phones.Add("123456789");

        person1.Phones.Add("123456788");

​

        var person2 = new Person { Name = "John", Surname = "Hall" };

        person2.Phones.Add("456789123");

​

        var person3 = new Person { Name = "Mamie", Surname = "William" };

        person3.Phones.Add("78946132d");

​

        var person4 = new Person { Name = "Doris", Surname = "Gravelle" };

​

        var person5 = new Person { Name = "Patricia", Surname = "Wilbur" };

        person5.Phones.Add("432789159");

        person5.Phones.Add("434589159");

        person5.Phones.Add("437789559");

        var houses = new List<House>() 

        { 

            new House { Address = "Poznań, św Marcin 12", Housemates = new List<Person>() { person1, person2 }},

            new House { Address = "Poznań, św Marcin 15", Housemates = new List<Person>() { person3, person4, person5 }} 

        };

        //Count all persons in houses

        //Write on console all phone numbers

        //Count all phone numbers that is valid (consist of 9 digit)

    }

}

​