using System;
using System.IO;

namespace Ulyanov_Abstract
{
    abstract class Person
    {
        public string Name;
        public int Birthdate;
        public string Faculty;

        public char Attach;

        abstract protected void print();
        abstract protected int getAge();
        protected bool CompareTo(ref Person arg1, ref Person arg2)
        {
            return arg1.Birthdate < arg2.Birthdate;
        }

        static public Person[] readFromFile(string inputFileName)
        {
            FileStream inputFile = new FileStream(inputFileName, FileMode.Open, FileAccess.Read);
            StreamReader inputReader = new StreamReader(inputFile);
            Int32 allocCnt = 0;
            while (inputReader.ReadLine() != null)
            {
                inputReader.ReadLine();
                inputReader.ReadLine();
                inputReader.ReadLine();
                inputReader.ReadLine();
                inputReader.ReadLine();
                allocCnt++;
            }

            Person[] arrPtr = new Person[allocCnt];
            string[] buff = new string[2];

            inputFile.Seek(0, SeekOrigin.Begin);

            for(Int32 i = 0; i < allocCnt; i++)
            {
                arrPtr[i].Name = inputReader.ReadLine();
                arrPtr[i].Birthdate = Convert.ToInt32(inputReader.ReadLine());
                arrPtr[i].Faculty = inputReader.ReadLine();

                buff[0] = inputReader.ReadLine();
                if( (buff[1] = inputReader.ReadLine() )
                    != "n/a")
                {
                    ((Teacher)arrPtr[i]).Position = buff[0];
                    ((Teacher)arrPtr[i]).Expierence = buff[1];
                    arrPtr[i].Attach = 'T';
                }
                else if( (buff[0] = inputReader.ReadLine())
                                 != "n/a")
                {
                    ((Student)arrPtr[i]).Course = buff[0];
                    arrPtr[i].Attach = 'S';
                }
                else
                {
                    arrPtr[i].Attach = 'A';
                }
            }

            inputFile.Close();

            return arrPtr;
        }
    }

    class Teacher : Person
    {
        public string Position;
        public string Expierence;

        override protected void print()
        {

        }

        override protected int getAge()
        {
            return 0;
        }
    }

    class Applicant : Person
    {

        override protected void print()
        {

        }

        override protected int getAge()
        {
            return 0;
        }
    }

    class Student : Person
    {
        public string Course;

        override protected void print()
        {

        }

        override protected int getAge()
        {
            return 0;
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            Person.readFromFile("source.txt");
        }
    }
}