Student with best grades (max 10 Students if created with factory)

student.rb

class Student

  MAX = 10
  
  @@students = []
  
  attr_accessor :name, :surname, :specialization, :grades

  def self.factory(hash={})
    return nil if @@students.length >= MAX
      
    student = Student.new(hash)
    @@students << student
    student
  end
      
  def initialize(hash={})

    @name = hash[:name].capitalize if hash.has_key? :name
    @surname = hash[:surname].capitalize if hash.has_key? :surname
    @specialization = hash[:specialization]
    @grades = hash[:grades]

  end

  def to_s
    "#{@name} #{@surname}, #{@specialization}, #{@grades}"
  end
  
  def self.best_student
    @@students.max_by { |s| s.grades }
  end
end

p Student.factory(name: "wojtek", surname: "duda", grades: 5)
p Student.factory(name: "ala", surname: "kowalska", grades: 6)
p Student.factory(name: "Monika", surname: "Nowak", grades: 2)

8.times do 
  p Student.factory(name: "wojtek", surname: "duda", grades: 5)
end

p Student.best_student