diff --git a/labs-solutions/08-binary-trees-traversal-exercises.ipynb b/labs-solutions/08-binary-trees-traversal-exercises.ipynb
index c6b0a4a6ac175bc71fb636d18752895426135dbc..cb64a5e3322f61645f1e9bab986b26e710d0632b 100644
--- a/labs-solutions/08-binary-trees-traversal-exercises.ipynb
+++ b/labs-solutions/08-binary-trees-traversal-exercises.ipynb
@@ -68,7 +68,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 81,
+   "execution_count": 98,
    "id": "51a49306-6cb7-4e84-9257-081793657848",
    "metadata": {
     "nbgrader": {
@@ -149,7 +149,6 @@
     "    return max(left_height, right_height) + 1\n",
     "\n",
     "def is_balanced(root):\n",
-    "    # un abre vide (None) est équilibré\n",
     "    if root is None: \n",
     "        return True\n",
     "    return is_balanced(root.right) and is_balanced(root.left) and abs(get_height(root.left) - get_height(root.right)) <= 1\n",
@@ -535,7 +534,6 @@
     "\n",
     "        visited.add(current)\n",
     "\n",
-    "        # Add left and right children to the stack if not visited\n",
     "        if current.left and current.left not in visited:\n",
     "            stack.append(current.left)\n",
     "        if current.right and current.right not in visited:\n",