public abstract class Person
{
    public string Surname { get; set; }
    public string Name { get; set; }
    public string SecondName { get; set; }
}

public class Student : Person
{
    public int GroupId { get; set; }
}

public class Teacher : Person
{
    public int Experience { get; set; } //стаж работы
}

public class StudentDto
{
    public string Surname { get; set; }
    public string Name { get; set; }
    public string SecondName { get; set; }

    public string ClassName { get; set; }
}

public interface IPerson
{
    string Surname { get; set; }
    string Name { get; set; }
    string SecondName { get; set; }
}

public class Student : IPerson
{
    public string Surname { get; set; }
    public string Name { get; set; }
    public string SecondName { get; set; }

    public int GroupId { get; set; }
}

public class Teacher : IPerson
{
    public string Surname { get; set; }
    public string Name { get; set; }
    public string SecondName { get; set; }

    public int Experience { get; set; }
}

public class StudentDto : IPerson
{
    public int GroupId { get; set; }
    public string Surname { get; set; }
    public string Name { get; set; }
    public string SecondName { get; set; }

    public string ClassName { get; set; }
}