diff --git a/Trees/SAT_Graph_Coloring.ipynb b/Trees/SAT_Graph_Coloring.ipynb
index fef93a0..9cc3656 100644
--- a/Trees/SAT_Graph_Coloring.ipynb
+++ b/Trees/SAT_Graph_Coloring.ipynb
@@ -4,7 +4,7 @@
   "metadata": {
     "colab": {
       "provenance": [],
-      "authorship_tag": "ABX9TyMogvy3h9v1JBEpREA36XTE",
+      "authorship_tag": "ABX9TyPST5sXc/A8YZYz0OFEURdn",
       "include_colab_link": true
     },
     "kernelspec": {
@@ -62,7 +62,6 @@
         "!pip install z3-solver\n",
         "from z3 import *\n",
         "import numpy as np\n",
-        "from itertools import combinations\n",
         "import geopandas as gpd\n",
         "import matplotlib.pyplot as plt"
       ],