using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace num1
{
    class Program
    {
        static void Main()
        {
            Enemy enem = new Enemy();
            IDamageable damageable = null;
            Kill(enem);
        }

        static void Kill(IDamageable damageable)
        {
            damageable.Damage(100);
            if (damageable.IsAlive())
            {
                Console.WriteLine("Цель ещё жива");
            }
            else
            {
                Console.WriteLine("Цель мертва");
            }
        }
    }


    class Enemy : IDamageable
    {
        private int _hp = 100;


        public void Damage(int damage)
        {
            _hp -= damage;
        }

        public bool IsAlive()
        {
            return _hp > 0;
        }
    }


    interface IDamageable
    {
        void Damage(int damage);
        bool IsAlive();
    }

}