diff --git a/module3/exo3/exercice.ipynb b/module3/exo3/exercice.ipynb
index 0ac49333db3bb8e80fc09d414554d10aef5841a8..c8c8a0ea8dab32227c696283ac1d55d8064a8876 100644
--- a/module3/exo3/exercice.ipynb
+++ b/module3/exo3/exercice.ipynb
@@ -9,7 +9,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 135,
+   "execution_count": 161,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -35,7 +35,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 136,
+   "execution_count": 162,
    "metadata": {},
    "outputs": [
     {
@@ -164,7 +164,7 @@
        "4     315.06        317.51       314.71  "
       ]
      },
-     "execution_count": 136,
+     "execution_count": 162,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -196,7 +196,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 137,
+   "execution_count": 163,
    "metadata": {},
    "outputs": [
     {
@@ -217,7 +217,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 138,
+   "execution_count": 164,
    "metadata": {},
    "outputs": [
     {
@@ -332,7 +332,7 @@
        "4  1958   5   21320  1958.3699  317.51  314.71  317.86  315.06  317.51  314.71"
       ]
      },
-     "execution_count": 138,
+     "execution_count": 164,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -350,7 +350,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 139,
+   "execution_count": 165,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -393,7 +393,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 140,
+   "execution_count": 166,
    "metadata": {},
    "outputs": [
     {
@@ -508,7 +508,7 @@
        "75  1964   4   23482  1964.2896 NaN NaN  321.83  319.45  321.83  319.45"
       ]
      },
-     "execution_count": 140,
+     "execution_count": 166,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -519,7 +519,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 141,
+   "execution_count": 167,
    "metadata": {},
    "outputs": [
     {
@@ -634,7 +634,7 @@
        "6  1958   7   21381  1958.5370  315.86  315.19  315.86  315.22  315.86  315.19"
       ]
      },
-     "execution_count": 141,
+     "execution_count": 167,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -653,7 +653,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 146,
+   "execution_count": 170,
    "metadata": {
     "scrolled": true
    },
@@ -662,6 +662,8 @@
      "name": "stdout",
      "output_type": "stream",
      "text": [
+      "(743, 10)\n",
+      "(743,)\n",
       "(745, 11)\n"
      ]
     },
@@ -754,7 +756,7 @@
        "      <td>314.99</td>\n",
        "      <td>317.45</td>\n",
        "      <td>315.16</td>\n",
-       "      <td>1958-07-01</td>\n",
+       "      <td>1958-06-01</td>\n",
        "    </tr>\n",
        "    <tr>\n",
        "      <th>4</th>\n",
@@ -768,7 +770,7 @@
        "      <td>315.06</td>\n",
        "      <td>317.51</td>\n",
        "      <td>314.71</td>\n",
-       "      <td>1958-08-01</td>\n",
+       "      <td>1958-07-01</td>\n",
        "    </tr>\n",
        "    <tr>\n",
        "      <th>...</th>\n",
@@ -796,7 +798,7 @@
        "      <td>412.05</td>\n",
        "      <td>408.55</td>\n",
        "      <td>412.06</td>\n",
-       "      <td>NaN</td>\n",
+       "      <td>2019-11-01</td>\n",
        "    </tr>\n",
        "    <tr>\n",
        "      <th>741</th>\n",
@@ -810,7 +812,7 @@
        "      <td>412.29</td>\n",
        "      <td>408.43</td>\n",
        "      <td>412.07</td>\n",
-       "      <td>NaN</td>\n",
+       "      <td>2019-12-01</td>\n",
        "    </tr>\n",
        "    <tr>\n",
        "      <th>742</th>\n",
@@ -824,7 +826,7 @@
        "      <td>412.54</td>\n",
        "      <td>410.28</td>\n",
        "      <td>412.56</td>\n",
-       "      <td>NaN</td>\n",
+       "      <td>2020-01-01</td>\n",
        "    </tr>\n",
        "    <tr>\n",
        "      <th>743</th>\n",
@@ -877,31 +879,38 @@
        "0       NaN  1958-03-01  \n",
        "1       NaN  1958-04-01  \n",
        "2    314.44  1958-05-01  \n",
-       "3    315.16  1958-07-01  \n",
-       "4    314.71  1958-08-01  \n",
+       "3    315.16  1958-06-01  \n",
+       "4    314.71  1958-07-01  \n",
        "..      ...         ...  \n",
-       "740  412.06         NaN  \n",
-       "741  412.07         NaN  \n",
-       "742  412.56         NaN  \n",
+       "740  412.06  2019-11-01  \n",
+       "741  412.07  2019-12-01  \n",
+       "742  412.56  2020-01-01  \n",
        "743  412.78         NaN  \n",
        "744  413.33         NaN  \n",
        "\n",
        "[745 rows x 11 columns]"
       ]
      },
-     "execution_count": 146,
+     "execution_count": 170,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
-    "data = data.dropna().copy()\n",
+    "#data = data.dropna().copy()\n",
+    "\n",
+    "print(data.shape)\n",
+    "\n",
     "period = [datetime.date(y,m,1) for y,m in zip(data['Yr'],data['Mn'])]\n",
     "period = pd.Series(period)\n",
+    "print(period.shape)\n",
+    "\n",
     "newdf = pd.concat([data,period],axis=1)\n",
+    "\n",
     "print(newdf.shape)\n",
     "#data['period'] = pd.Series([datetime.date(y,m,1) for y,m in zip(data['Yr'],data['Mn'])])\n",
     "\n",
+    "period\n",
     "#data1 = data1.set_index('period')   \n",
     "#data\n",
     "newdf"