using System;

namespace Laba3
{
    class Human
    {
        private string _name;
        private int _age;

        public string Name
        {
            set
            {
                if (value == "")
                {
                    Console.WriteLine("Enter your name, please.");
                }
                else
                {
                    _name = value;
                }
            }
        }

        public int Age
        {
            set
            {
                if (value <= 0)
                {
                    Console.WriteLine("Should be positive !");
                }
                else
                {
                    _age = value;
                }
            }
            get { return _age; }
        }



    public void out_info()
        {
            Console.WriteLine($"Name: {_name}   Age: {Age}");
        }
    }

    class Student:Human
    {
        public float average_grade;
        private int _class;
        public bool scholarship;

        public int Class {
            set
            {
                if (value <= 0)
                {
                    Console.WriteLine("Check your info about your studying year!");
                }
                else
                {
                    _class = value;
                }
            }
            get { return _class; }
        }
    }
    class Program
    {

        static void Main(string[] args)
        {
           Human ellia = new Human();
           Student feda = new Student();
           feda.Age = 19;
           feda.out_info();
           ellia.out_info();

           ellia.Age = -9;
           ellia.Name = "Ellia";
           ellia.out_info();
        }
    }
}