using System;

​

public class Program

{

    class Date

    {

        private int day;

        private int month;

        private int year;

        public Date(int day, int month, int year)

        {

            this.day = day;

            this.month = month;

            this.year = year;

        }

​

        public Date(Date c)

        {

            this.day = c.day;

            this.month = c.month;

            this.year = c.year;

        }

​

        public int GetDay()

        {

            return this.day;

        }

​

        public int GetMonth()

        {

            return this.month;

        }

​

        public int GetYear()

        {

            return this.year;

        }

​

        public void SetDay(int day)

        {

            this.day = day;

        }

​

        public void SetMonth(int month)

        {

            this.month = month;

        }

​

        public void Setyear(int year)

        {

            this.year = year;

        }

​

        public int CompareTo(Date d)

        {

            if (this.year == d.year)

            {

                if (this.month == d.month)

                {

                    return this.day - d.day;

                }

                else

                {

                    return this.month - d.month;

                }

            }

            else

            {

                return this.year - d.year;

            }

        }

​

        public string Tostring()

        {

            return this.day + "/" + this.month + "/" + this.year;

        }

​

        public void build()

        {

            int day, month, year;

            Console.WriteLine("enter day");

            day = int.Parse(Console.ReadLine());

            Console.WriteLine("enter month");

            month = int.Parse(Console.ReadLine());

            Console.WriteLine("enter year");

            year = int.Parse(Console.ReadLine());

            Date d = new Date(day,month,year);

        }

    }

​

    class Student

    {

        private string name;

        private Date birth;

        private int[] grades;

        public Student(string name, Date birth, int[] grades)

        {

            this.name = name;

            this.birth = birth;

            this.grades = grades;

        }

​

        public Student(Student d)

        {

            this.name = d.name;

            this.birth = d.birth;

            this.grades = d.grades;

        }

​

        public string GetName()

        {

            return this.name;

        }

​

        public Date GetBirth()

        {

            return this.birth;

        }

​

        public int[] GetGrades()

        {

            return this.grades;

        }

​

        public void SetName(string name)

        {

            this.name = name;

        }

​

        public void SetBirth(Date birth)

        {

            this.birth = birth;

        }

​

        public void SetGrades(int[] grades)

        {

            this.grades = grades;

        }

​

        public double AvgGrades()

        {

            int avg = 0;

            for (int i = 0; i < this.grades.Length; i++)

            {

                avg = avg + this.grades[i];

            }

​

            return avg / this.grades.Length;

        }

​

        public bool Older(Student t)

        {

            if (this.birth.CompareTo(t.birth) < 0)

            {

                return true;

            }

            else

            {

                return false;

            }

        }

​

        public string ToString(Student t)

        {

            return "Name: " + this.name + ", " + "Birth: " + this.birth + ", " + "Grades:" + this.grades + ", " + "Average; " + t.AvgGrades();

        }

        public void BuildStudent()

        {

            string name;

            int[] grades = new int[4];

            int day,month,year;

            Console.WriteLine("enter name");

            name = Console.ReadLine();

            this.name = name;

            Console.WriteLine("enter day");

            day = int.Parse(Console.ReadLine());

            Console.WriteLine("enter month");

            month = int.Parse(Console.ReadLine());

            Console.WriteLine("enter year");

            year = int.Parse(Console.ReadLine());

            Date d = new Date(day,month,year);

            for(int i = 0; i < 4; i++)

            {

                Random rnd = new Random();

                int num = rnd.Next(40 , 101);

                grades[i] = num;

            }

            grades = this.grades;

        }

    }

​

    public static void Main()

    {

        Date date = new Date(date.build());

        Console.WriteLine("your date is" + date.ToString());

        Date date2 = new Date(1, 12, 1980);

        Console.WriteLine("your secound date is" + date2.ToString());

        Console.WriteLine("if the number is positive that's mean that the first date is smaller then the secound date " + date.CompareTo(date2));

        Student t = new Student(t.BuildStudent());

        t.BuildStudent();

    }

}