Person

using System;
using System.Text;

namespace ExercisesInheritance
{
    class Program
    {
        static void Main()
        {
            string name = Console.ReadLine();
            int age = int.Parse(Console.ReadLine());

            try
            {
                Child child = new Child(name, age);
                Console.WriteLine(child);
            }
            catch (ArgumentException ae)
            {
                Console.WriteLine(ae.Message);
            }
        }

    }

    public class Child : Person
    {
        public Child(string name, int age) : base(name, age)
        {

        }

        public override int Age
        {
            get { return base.Age; }
            protected set
            {
                if (value >= 15)
                {
                    throw new ArgumentException("Child’s age must be less than 15!");
                }

                base.Age = value;
            }
        }
    }

    public class Person
    {
        private string name;
        private int age;

        public Person(string name, int age)
        {
            this.Age = age;
            this.Name = name;
        }

        public virtual string Name
        {
            get { return this.name; }
            protected set
            {
                if (value.Length < 3  || string.IsNullOrWhiteSpace(value))
                {
                    throw new ArgumentException("Name’s length should not be less than 3 symbols!");
                }
                this.name = value;
            }
        }

        public virtual int Age
        {
            get { return this.age; }
            protected set
            {
                if (value < 0)
                {
                    throw new ArgumentException("Age must be positive!");
                }
                this.age = value;
            }
        }

        public override string ToString()
        {
            StringBuilder sb = new StringBuilder();
            sb.Append($"Name: {this.Name}, Age: {this.Age}");

            return sb.ToString();
        }
    }
}