diff --git a/BST.py b/BST.py
index 2c3a999..ddbe41f 100644
--- a/BST.py
+++ b/BST.py
@@ -51,15 +51,32 @@ class BST:
         in_order_rec(self.root, ret)
         return ret
 
+    def height(self):
+        return self.root.height()
+
+
+class BalancedBST(BST):
+    def by_index(self, i):
+        instructions = []
+        while i > 0:
+            instructions.append(i & 1 == 0)
+            i = (i - 1) // 2
+
+        current = self.root
+        while len(instructions) > 0:
+            go_right = instructions.pop()
+            if go_right:
+                current = current.right
+            else:
+                current = current.left
+        return current
+
     @classmethod
-    def balance(cls, list_param):
+    def balanced(cls, list_param):
         tree = cls()
         add_rec(0, len(list_param) - 1, list_param, tree)
         return tree
 
-    def height(self):
-        return self.root.height()
-
 
 def in_order_rec(top, ret):
     if top is None:
@@ -82,10 +99,11 @@ def add_rec(start, end, list_param, tree: BST):
 if __name__ == "__main__":
     test = 17
     list_param = list(range(test))
-    tree = BST.balance(list_param)
+    tree = BalancedBST.balanced(list_param)
     tree2 = BST()
     for i in range(test):
         tree2.add(i)
     r = list(node.value for node in tree.in_order())
     r2 = list(node.value for node in tree2.in_order())
     assert r == r2
+    tree.by_index(6)