diff --git a/komissarovgo/docs/data/CodePhoneBook.py b/komissarovgo/docs/data/CodePhoneBook.py
index 66dfdf0..167b324 100644
--- a/komissarovgo/docs/data/CodePhoneBook.py
+++ b/komissarovgo/docs/data/CodePhoneBook.py
@@ -65,6 +65,8 @@ def ll_list_all(head):
     records.sort(key=lambda x: x[0])
     return records
 
+
+
 # 2. Hash Function
 
 def hash_function(name, table_size):
@@ -101,4 +103,81 @@ def ht_list_all(buckets):
             records.append((current['name'], current['phone']))
             current = current['next']
     records.sort(key=lambda x: x[0])
+    return records
+
+
+
+#3. Tree function
+
+
+def bst_insert(root, name, phone):
+    
+    if root is None:
+        return {'name': name, 'phone': phone, 'left': None, 'right': None}
+    
+    if name < root['name']:
+        root['left'] = bst_insert(root['left'], name, phone)
+    elif name > root['name']:
+        root['right'] = bst_insert(root['right'], name, phone)
+    else:
+        root['phone'] = phone
+    
+    return root
+
+
+def bst_find(root, name):
+    
+    current = root
+    while current is not None:
+        if name == current['name']:
+            return current['phone']
+        elif name < current['name']:
+            current = current['left']
+        else:
+            current = current['right']
+    return None
+
+
+def bst_find_min(node):
+    
+    current = node
+    while current['left'] is not None:
+        current = current['left']
+    return current
+
+
+def bst_delete(root, name):
+    
+    if root is None:
+        return None
+    
+    if name < root['name']:
+        root['left'] = bst_delete(root['left'], name)
+    elif name > root['name']:
+        root['right'] = bst_delete(root['right'], name)
+    else:
+        if root['left'] is None:
+            return root['right']
+        elif root['right'] is None:
+            return root['left']
+        
+        min_node = bst_find_min(root['right'])
+        root['name'] = min_node['name']
+        root['phone'] = min_node['phone']
+        root['right'] = bst_delete(root['right'], min_node['name'])
+    
+    return root
+
+
+def bst_list_all(root):
+    
+    records = []
+    
+    def inorder_traversal(node):
+        if node is not None:
+            inorder_traversal(node['left'])
+            records.append((node['name'], node['phone']))
+            inorder_traversal(node['right'])
+    
+    inorder_traversal(root)
     return records
\ No newline at end of file