diff --git a/lab3_task1_funcation_block_arg/main.rb b/lab3_task1_funcation_block_arg/main.rb
index 20c5ebe..0f80877 100644
--- a/lab3_task1_funcation_block_arg/main.rb
+++ b/lab3_task1_funcation_block_arg/main.rb
@@ -1,9 +1,9 @@
 
 def indices_sorted_by_descending_values(array)
-    indices = array.each_with_index.to_a
-    sorted_indices = indices.sort_by { |(element, index)| -element }
-    result = sorted_indices.map { |(element, index)| index }
-    result
+    array.each_with_index.to_a
+      .sort_by { |(element, index)| -element }
+      .map { |(element, index)| index }
+    
 end
 
 
diff --git a/lab3_task3_html_tree/main.rb b/lab3_task3_html_tree/main.rb
new file mode 100644
index 0000000..053190f
--- /dev/null
+++ b/lab3_task3_html_tree/main.rb
@@ -0,0 +1,95 @@
+require 'nokogiri'
+
+class HtmlTree
+  include Enumerable
+
+  def initialize(html)
+    puts "Input HTML:\n#{html.inspect}" # Проверяем входной HTML
+    @root = parse_html(html)
+    raise "Parsed HTML tree is empty" if @root.nil?
+  end
+
+  def each(order = :breadth_first, &block)
+    case order
+    when :breadth_first
+      breadth_first_traversal(&block)
+    when :depth_first
+      depth_first_traversal(&block)
+    else
+      raise ArgumentError, "Unknown order: #{order}"
+    end
+  end
+
+  private
+
+  def parse_html(html)
+    doc = Nokogiri::HTML::DocumentFragment.parse(html)
+    root_node = doc.at_css('body') || doc.children.find(&:element?) || doc.root
+    return nil if root_node.nil? || root_node.children.empty?
+
+    build_tree(root_node)
+  end
+
+  def build_tree(node)
+    if node.element?
+      children = node.children.map { |child| build_tree(child) }.compact
+      HtmlTag.new(node.name, node.attributes.transform_values(&:value), children)
+    elsif node.text? && !node.content.strip.empty?
+      HtmlTag.new("text", { "content" => node.content.strip }, [])
+    end
+  end
+
+  def breadth_first_traversal
+    queue = [@root].compact
+    until queue.empty?
+      current = queue.shift
+      next if current.nil?
+
+      yield current
+      queue.concat(current.children.compact) if current.has_children?
+    end
+  end
+
+  def depth_first_traversal(node = @root, &block)
+    return if node.nil?
+
+    yield node
+    node.children.compact.each { |child| depth_first_traversal(child, &block) } if node.has_children?
+  end
+end
+
+class HtmlTag
+  attr_reader :name, :attributes, :children
+
+  def initialize(name, attributes, children = [])
+    @name = name
+    @attributes = attributes
+    @children = children
+  end
+
+  def has_children?
+    !@children.empty?
+  end
+
+  def to_s
+    "#{@name} #{@attributes}"
+  end
+end
+
+html = <<-HTML
+  <div id="root">
+    <p class="text">Hello, world!</p>
+    <ul>
+      <li>Item 1</li>
+      <li>Item 2</li>
+    </ul>
+  </div>
+HTML
+
+tree = HtmlTree.new(html)
+
+puts "Traversal in breadth-first order:"
+tree.each(:breadth_first) { |tag| puts tag }
+
+puts "\nTraversal in depth-first order:"
+tree.each(:depth_first) { |tag| puts tag }
\ No newline at end of file