diff --git a/examples/s4e9.ipynb b/examples/s4e9.ipynb
index 529615a..cb94c79 100644
--- a/examples/s4e9.ipynb
+++ b/examples/s4e9.ipynb
@@ -349,6 +349,93 @@
       "/ext3/miniconda3/lib/python3.9/site-packages/datamart_profiler/core.py:199: FutureWarning: Downcasting object dtype arrays on .fillna, .ffill, .bfill is deprecated and will change in a future version. Call result.infer_objects(copy=False) instead. To opt-in to the future behavior, set `pd.set_option('future.no_silent_downcasting', True)`\n",
       "  data = data.astype(object).fillna('').astype(str)\n",
       "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n"
+     ]
+    },
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "training, score: 55164.69642711305...\n"
+     ]
+    },
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/preprocessing/_label.py:114: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples, ), for example using ravel().\n",
+      "  y = column_or_1d(y, warn=True)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/datamart_profiler/core.py:199: FutureWarning: Downcasting object dtype arrays on .fillna, .ffill, .bfill is deprecated and will change in a future version. Call result.infer_objects(copy=False) instead. To opt-in to the future behavior, set `pd.set_option('future.no_silent_downcasting', True)`\n",
+      "  data = data.astype(object).fillna('').astype(str)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n"
+     ]
+    },
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "training, score: 62603.8140657158...\n"
+     ]
+    },
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/preprocessing/_label.py:114: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples, ), for example using ravel().\n",
+      "  y = column_or_1d(y, warn=True)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/datamart_profiler/core.py:199: FutureWarning: Downcasting object dtype arrays on .fillna, .ffill, .bfill is deprecated and will change in a future version. Call result.infer_objects(copy=False) instead. To opt-in to the future behavior, set `pd.set_option('future.no_silent_downcasting', True)`\n",
+      "  data = data.astype(object).fillna('').astype(str)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
+      "  return fit_method(estimator, *args, **kwargs)\n"
+     ]
+    },
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "training, score: 57468.024932105174...\n"
+     ]
+    },
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/preprocessing/_label.py:114: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples, ), for example using ravel().\n",
+      "  y = column_or_1d(y, warn=True)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/datamart_profiler/core.py:199: FutureWarning: Downcasting object dtype arrays on .fillna, .ffill, .bfill is deprecated and will change in a future version. Call result.infer_objects(copy=False) instead. To opt-in to the future behavior, set `pd.set_option('future.no_silent_downcasting', True)`\n",
+      "  data = data.astype(object).fillna('').astype(str)\n",
+      "/ext3/miniconda3/lib/python3.9/site-packages/sklearn/base.py:1474: DataConversionWarning: A column-vector y was passed when a 1d array was expected. Please change the shape of y to (n_samples,), for example using ravel().\n",
       "  return fit_method(estimator, *args, **kwargs)\n"
      ]
     }
@@ -399,7 +486,7 @@
     "    \n",
     "    \n",
     "    best_generator = None\n",
-    "    best_score = 0\n",
+    "    best_score = 99999\n",
     "    \n",
     "\n",
     "    for i in range(n_trails):\n",
@@ -445,7 +532,7 @@
     "    \n",
     "            scores = cross_val_score(pipeline, X_gen, y_gen, scoring=make_scorer(mean_squared_error), cv=5)\n",
     "            score = sum(scores) / len(scores)\n",
-    "            if score > best_score:\n",
+    "            if score < best_score:\n",
     "                best_score = score\n",
     "                best_generator = generator\n",
     "            \n",