diff --git a/.gitignore b/.gitignore
index 953cd6f..4156916 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,4 @@
 *.tar.gz
 /9780596000851-master/
+
+.dir-locals.el
\ No newline at end of file
diff --git a/BST.py b/BST.py
index d1ded9a..c9b1e8a 100644
--- a/BST.py
+++ b/BST.py
@@ -4,6 +4,15 @@ class BSTNode:
         self.left = None
         self.right = None
 
+    def height(self):
+        lh = 0
+        rh = 0
+        if self.left is not None:
+            lh = self.left.height()
+        if self.right is not None:
+            rh = self.right.height()
+        return 1 + max(lh, rh)
+
 
 class BST:
     def __init__(self):
@@ -49,7 +58,7 @@ class BST:
         return tree
 
     def height(self):
-        return rec_height(self.root)
+        return self.root.height()
 
 
 def inOrderRec(top, ret):
@@ -62,12 +71,6 @@ def inOrderRec(top, ret):
         inOrderRec(top.right, ret)
 
 
-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