diff --git a/module2/exo4/exercice.ipynb b/module2/exo4/exercice.ipynb
index 0bbbe371b01e359e381e43239412d77bf53fb1fb..7b00cba2df5432a59618eb00bc76280efbf2a44a 100644
--- a/module2/exo4/exercice.ipynb
+++ b/module2/exo4/exercice.ipynb
@@ -1,6 +1,18 @@
 {
- "cells": [],
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "hideCode": true,
+    "hidePrompt": true
+   },
+   "outputs": [],
+   "source": []
+  }
+ ],
  "metadata": {
+  "hide_code_all_hidden": true,
   "kernelspec": {
    "display_name": "Python 3",
    "language": "python",
@@ -16,10 +28,9 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.6.3"
+   "version": "3.6.4"
   }
  },
  "nbformat": 4,
  "nbformat_minor": 2
 }
-