diff --git a/BoriskovaDV/docs/data/1-st-exercise/bst_phonebook.py b/BoriskovaDV/docs/data/1-st-exercise/bst_phonebook.py
new file mode 100644
index 0000000..0f5e017
--- /dev/null
+++ b/BoriskovaDV/docs/data/1-st-exercise/bst_phonebook.py
@@ -0,0 +1,71 @@
+def create_node(name, phone):
+    return {'name': name, 'phone': phone, 'left': None, 'right': None}
+
+def bst_insert(root, name, phone):
+    if root is None:
+        return create_node(name, phone)
+    
+    if name == root['name']:
+        root['phone'] = phone
+    elif name < root['name']:
+        root['left'] = bst_insert(root['left'], name, phone)
+    else:
+        root['right'] = bst_insert(root['right'], name, phone)
+    return root
+
+def bst_find(root, name):
+    if root is None:
+        return None
+    if name == root['name']:
+        return root['phone']
+    elif name < root['name']:
+        return bst_find(root['left'], name)
+    else:
+        return bst_find(root['right'], name)
+
+def _find_min(node):
+    while node['left'] is not None:
+        node = node['left']
+    return node
+
+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']
+        if root['right'] is None:
+            return root['left']
+        min_node = _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):
+    result = []
+    def inorder(node):
+        if node is None:
+            return
+        inorder(node['left'])
+        result.append((node['name'], node['phone']))
+        inorder(node['right'])
+    inorder(root)
+    return result
+
+if __name__ == '__main__':
+    root = None
+    root = bst_insert(root, 'Иван', '123-456')
+    root = bst_insert(root, 'Борис', '789-012')
+    root = bst_insert(root, 'Анна', '345-678')
+    root = bst_insert(root, 'Иван', '111-222')
+    print(bst_list_all(root))
+    print(bst_find(root, 'Иван'))
+    print(bst_find(root, 'Петр'))
+    root = bst_delete(root, 'Борис')
+    print(bst_list_all(root))
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