using System;

using System.Text;

public class Program

{

    public abstract record Person(string FirstName, string LastName)

    {

        public sealed override string ToString()

        {

            StringBuilder stringBuilder = new StringBuilder();

            stringBuilder.Append("Base Record"); // type name

            stringBuilder.Append(" { ");

            if (PrintMembers(stringBuilder))

            {

                stringBuilder.Append(" ");

            }

            stringBuilder.Append("}");

            return stringBuilder.ToString();

        }

    }

    public record Teacher(string FirstName, string LastName, int Grade): Person(FirstName, LastName) 

    {