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

namespace lab8
{
    class MainClass
    {
        delegate void Print();
        delegate string Merge(int a, string b, string c);
        delegate void Merge2(Print x, string d);

        public class MyEvent
        {
            public delegate void Get();
            public event Get zzz;

            public void Go()
            {
                if(zzz != null)
                    zzz();
            }
        }

        public class Person : IComparable<Person>
        {
            protected int age;
            protected string name, surname;

            public int CompareTo(Person other)
            {
                return other.age.CompareTo(this.age);
            }

            public Person(int age, string name, string surname)
            {
                try
                {
                    if (age < 0) throw new Exception();
                    this.age = age;
                    this.name = name;
                    this.surname = surname;
                }
                catch
                {
                    Console.WriteLine("Error : Age < 0");
                    //Environment.Exit(0);
                }

            }

            public virtual void Print()
            {
                Merge Foo = (x, y, z) => ("Age = " + x + "\nName = " + y + "\nSurname = " + z);
                string ans = Foo(age, name, surname);
                Console.WriteLine(ans);
            }
        }

        public class Student : Person
        {
            protected string university;

            public Student(int age, string name, string surname, string university)
                : base(age, name, surname)
            {
                this.university = university;
            }

            readonly Merge2 Foo = delegate (Print func, string x)
            {
                 func();
                 Console.WriteLine("University = " + x + "\n");
            };

            public override void Print()
            {
                Foo(base.Print, university);
            }

        }

        public static void Main(string[] args)
        {
            List<Person> arr = new List<Person>();
            arr.Add(new Person(-1, "qqq", "fdfd"));
            arr.Add(new Person(132, "pppp", "fdjf"));
            arr.Add(new Student(1333, "fjkd", "qqq", "222"));

            MyEvent x = new MyEvent();

            foreach(var item in arr)
            {
                x.zzz += item.Print;
            }
            x.Go();

        }

    }
}