diff --git a/Notebooks/Chap07/7_3_Initialization.ipynb b/Notebooks/Chap07/7_3_Initialization.ipynb
index 673d273..fca1bfe 100644
--- a/Notebooks/Chap07/7_3_Initialization.ipynb
+++ b/Notebooks/Chap07/7_3_Initialization.ipynb
@@ -4,7 +4,6 @@
   "metadata": {
     "colab": {
       "provenance": [],
-      "authorship_tag": "ABX9TyOaATWBrwVMylV1akcKtHjt",
       "include_colab_link": true
     },
     "kernelspec": {
@@ -250,7 +249,7 @@
         "# Main backward pass routine\n",
         "def backward_pass(all_weights, all_biases, all_f, all_h, y):\n",
         "  # Retrieve number of layers\n",
-        "  K = all_weights\n",
+        "  K = len(all_weights) - 1\n",
         "\n",
         "  # We'll store the derivatives dl_dweights and dl_dbiases in lists as well\n",
         "  all_dl_dweights = [None] * (K+1)\n",