diff --git a/BST.py b/BST.py
index 846c46f..d1ded9a 100644
--- a/BST.py
+++ b/BST.py
@@ -45,11 +45,11 @@ class BST:
     @classmethod
     def balance(cls, list_param):
         tree = cls()
-        add_rec(0, len(list_param) // 2, len(list_param), list_param, tree)
+        add_rec(0, len(list_param) - 1, list_param, tree)
         return tree
 
-
-iteration_count = 0
+    def height(self):
+        return rec_height(self.root)
 
 
 def inOrderRec(top, ret):
@@ -62,24 +62,27 @@ def inOrderRec(top, ret):
         inOrderRec(top.right, ret)
 
 
-def add_rec(start, mid, end, list_param, tree: BST):
-    global iteration_count
-    iteration_count += 1
-    if iteration_count < 60:
-        if start != mid and mid != end:
-            print(mid)
-            add_rec(start, (start + mid) // 2, mid, list_param, tree)
-            tree.add(list_param[mid])
-            add_rec(mid, (mid + end) // 2, end, list_param, tree)
-    else:
-        breakpoint()
+def rec_height(node: BSTNode):
+    if node is None:
+        return 0
+    return 1 + max(map(rec_height, (node.left, node.right)))
+
+
+def add_rec(start, end, list_param, tree: BST):
+    if end - start >= 0:
+        mid = (start + end) // 2
+        tree.add(list_param[mid])
+        add_rec(start, mid - 1, list_param, tree)
+        add_rec(mid + 1, end, list_param, tree)
 
 
 if __name__ == "__main__":
-    list_param = list(range(17))
+    test = 17
+    list_param = list(range(test))
     tree = BST.balance(list_param)
     tree2 = BST()
-    for i in range(17):
+    for i in range(test):
         tree2.add(i)
     r = list(node.value for node in tree.inOrder())
     r2 = list(node.value for node in tree2.inOrder())
+    assert r == r2