---

using System;

public class Student
{
    private int _course;

    public string FirstName { get; set; }
    public string FamilyName { get; set; }

    public int Course
    {
        get { return _course; }
        set
        {
            if (value < 1 || value > 4)
                throw new ArgumentOutOfRangeException(nameof(value), "Need to be 1-4");
            _course = value;
        }
    }
    public string GetInfo()
    {
        string yearSuffix = Course == 1 ? "st" : Course == 2 ? "nd" : Course == 3 ? "rd" : "th";
        return $"{FamilyName}{FirstName} , {Course}{yearSuffix} year";
    }
}


public class Theromometer
{
    private double _celsius;

    public double Celsius
    {
        get { return _celsius; }
        set
        {
            if (value < -273.15)
                throw new ArgumentException("Cannot be below zero");
            _celsius = value;
        }
    }
    public double Fahrenheit
    {
        get { return Celsius * 9 / 5 + 32; }
    }
}

public class Book
{
    public int Pages { get; set; }
    public int Year { get; set; }
    public string Author { get; set; }
    public string Title { get; set; }

    public Book() : this("Untitled", "Unknown", 2000, 1)
    {
    }

    public Book(string title, string author) : this(title,author,2000,1)
    {

    }

    public Book(string title, string author, int pages, int year)
    {
        Title = title;
        Author = author;
        Pages = pages;
        Year = year;
    }
}

public class Rectangle
{
    private double _width;
    private double _height;

    public double Width
    {
        get { return _width; }
        set
        {
            if (value < 0) throw new ArgumentException("Greater than 0");
            _width = value;
        }
    }
    public double Height
    {
        get { return _height; }
        set
        {
            if (value < 0) throw new ArgumentException("Greater than 0");
            _height = value;
        }
    }
    public double Area => Width * Height;
    public double Perimeter => 2 * (Width * Height);

    public Rectangle(double width, double height)
    {
        _width = width;
        _height = height;
    }