using System;
using System.Collections.Generic;
using System.Linq;

namespace Holiday
{
  public abstract class Animal
  {
    public abstract int NailLength { get; set; }
    public bool IsAlive { get; private set; }

    public abstract void Move();

    public virtual void Eat(Animal animal)
    {
      if (animal != null)
      {
        if (animal.GetType() != GetType())
        {
          animal.Die();
        }
      }
    }

    public virtual void Die()
    {
      Console.WriteLine("Ой-ой");
    }
  }

  public class Swimming : Animal
  {
    public override int NailLength { get; set; }

    public override void Move()
    {
      Console.WriteLine("Буль-буль");
    }
  }

  public class Walking : Animal
  {
    public override int NailLength { get; set; }

    public override void Move()
    {
      throw new NotImplementedException();
    }

    public override void Eat(Animal animal)
    {
      if (animal != null)
      {
        var walking = animal as Walking;
        if (walking != null && walking.NailLength <= NailLength || walking == null)
        {
          animal.Die();
        }
      }
    }
  }

  public class God
  {
    public God()
    {
      Animals = new List<Animal>();
    }

    public List<Animal> Animals { get; private set; }

    public void KillAll()
    {
      foreach (Animal animal in Animals.Where(a => a.IsAlive))
      {
        animal.Die();
      }
    }
  }

  public class Factory
  {
    public God God { get; private set; }

    public Factory()
    {
      God = new God();
    }

    public IEnumerable<Animal> Load(string path)
    {
      for (int i = 0; i < 5; i++)
      {
        var animal = new Swimming();
        God.Animals.Add(animal);

        yield return animal;
      }
    }
  }
}