diff --git a/lab2/README.md b/lab2/README.md
index 561d38d..28468bf 100644
--- a/lab2/README.md
+++ b/lab2/README.md
@@ -5,6 +5,21 @@
 
 ```mermaid
 classDiagram
+    class BinarySearchTree {
+        - root : Node
+        + add(student : Student) : void
+        + each(&block) : void
+        - insert(node : Node, student : Student) : Node
+        - in_order_traversal(node : Node, &block) : void
+    }
+
+    class Node {
+        - student : Student
+        - left : Node
+        - right : Node
+        + Node(student : Student)
+    }
+
     class Contact {
         - phone : String?
         - telegram : String?
@@ -39,7 +54,7 @@ classDiagram
 
     class StudentShort {
         - surname_initials : String
-        - contact : String
+        - contact : Contact
         + StudentShort(id : String, git : String, surname_initials : String, contact : Contact)
         + from_student(student : Student) : StudentShort
         + from_string(id : String, info_string : String) : StudentShort
@@ -50,7 +65,8 @@ classDiagram
         - surname : String
         - name : String
         - patronymic : String
-        + Student(id : String, git : String, contact : Contact, surname : String, name : String, patronymic : String)
+        - birth_date : Date
+        + Student(id : String, git : String, contact : Contact, surname : String, name : String, patronymic : String, birth_date : Date)
         + from_string(student_string : String) : Student
         + surname_and_initials() : String
         + to_s() : String
@@ -58,6 +74,8 @@ classDiagram
         - validate_student()
     }
 
+    BinarySearchTree o-- Node
+    Node o-- Student
     Contact <|-- Person
     Person <|-- Student
     Person <|-- StudentShort
diff --git a/lab2/student.rb b/lab2/student.rb
index 3902575..2ca1cb8 100644
--- a/lab2/student.rb
+++ b/lab2/student.rb
@@ -8,10 +8,10 @@ class Student < Person
 
   def initialize(id:, git:, contact:, surname:, name:, patronymic:, birth_date:)
     super(id: id, git: git, contact: contact)
-    @surname = surname
-    @name = name
-    @patronymic = patronymic
-    @birth_date = birth_date
+    self.surname = surname
+    self.name = name
+    self.patronymic = patronymic
+    self.birth_date = birth_date
 
     validate_student
   end
@@ -58,6 +58,34 @@ class Student < Person
     "#{surname_and_initials}, Git: #{@git}, Contact: #{contact_info}, Birth Date: #{@birth_date}"
   end
 
+  def surname=(surname)
+    raise ArgumentError, 'Surname is required' if surname.nil? || surname.strip.empty?
+    raise ArgumentError, "Invalid surname format: #{surname}" unless valid_name?(surname)
+
+    @surname = surname
+  end
+
+  def name=(name)
+    raise ArgumentError, 'Name is required' if name.nil? || name.strip.empty?
+    raise ArgumentError, "Invalid name format: #{name}" unless valid_name?(name)
+
+    @name = name
+  end
+
+  def patronymic=(patronymic)
+    raise ArgumentError, 'Patronymic is required' if patronymic.nil? || patronymic.strip.empty?
+    raise ArgumentError, "Invalid patronymic format: #{patronymic}" unless valid_name?(patronymic)
+
+    @patronymic = patronymic
+  end
+
+  def birth_date=(birth_date)
+    raise ArgumentError, 'Birth date is required' if birth_date.nil?
+    raise ArgumentError, "Invalid birth date: #{birth_date}" unless birth_date.is_a?(Date)
+
+    @birth_date = birth_date
+  end
+
   private
 
   def validate_student