﻿namespace Human
{
    using System;

    public class Student : Human
    {
        private int grade;

        public Student(string firstName, string secondName, int grade)
            : base(firstName, secondName)
        {
            this.Grade = grade;
        }

        public int Grade
        {
            get
            {
                return this.grade;
            }
            set
            {
                if (value < 0)
                {
                    throw new ArgumentException("Grade can not be a negative number");
                }
                this.grade = value;
            }
        }
    }
}
