14

using System;
using System.Collections.Generic;

namespace Drafty
{
    class Program
    {
        interface Mobile
        {
            public void Ring();

            public void Call();

            public void GenerateSerialNumber();
        }

        interface SiemensMobile : Mobile
        {
            public void PlaySomeTuneOnButtons();
        }

        class AVG15 : SiemensMobile
        {
            private string ownerName;
            public string OwnerName { get { return ownerName; } }

            private string serialNumber = null;
            public string SerialNumber { get { return serialNumber; } }

            public AVG15(string ownerName)
            {
                GenerateSerialNumber();
                this.ownerName = ownerName;
            }

            public AVG15()
            {
                GenerateSerialNumber();
                this.ownerName = "unknown user";
            }

            public void Call()
            {
                Console.WriteLine("неправильно указан номер");
            }

            public void Call(string number)
            {
                Console.WriteLine("звоним на номер " + number);
            }

            public void PlaySomeTuneOnButtons()
            {
                Console.WriteLine("тун тун тун");
            }

            public void Ring()
            {
                Console.WriteLine("трыыыыыыыыыынь");
            }

            public void GenerateSerialNumber()
            {
                if (this.serialNumber is null)
                {
                    Random random = new Random();
                    this.serialNumber = random.Next(0, 100000000).ToString();
                }
            }

            public override string ToString()
            {
                return $"owner name: {this.OwnerName} serial number: {this.serialNumber}";
            }
        }


        static void Main(string[] args)
        {
            AVG15 mobile = new AVG15("Julia");
            mobile.Call();
            mobile.Call("+375295498611");

            mobile.Ring();
            Console.WriteLine(mobile.ToString());
        }
    }
}