diff --git a/ipython/EulerProblem066.ipynb b/ipython/EulerProblem066.ipynb
index a761e06..d7e4b38 100644
--- a/ipython/EulerProblem066.ipynb
+++ b/ipython/EulerProblem066.ipynb
@@ -122,7 +122,9 @@
   {
    "cell_type": "code",
    "execution_count": 43,
-   "metadata": {},
+   "metadata": {
+    "collapsed": true
+   },
    "outputs": [],
    "source": [
     "def gcd(a, b):\n",
@@ -167,7 +169,9 @@
   {
    "cell_type": "code",
    "execution_count": 48,
-   "metadata": {},
+   "metadata": {
+    "collapsed": true
+   },
    "outputs": [],
    "source": [
     "def get_minimal_solution(d):\n",
@@ -246,7 +250,7 @@
   }
  ],
  "metadata": {
-  "completion_date": "Tue, 22 Jan 2019, 05:10",
+  "completion_date": "Mon, 28 Jan 2019, 21:08",
   "kernelspec": {
    "display_name": "Python 3",
    "language": "python3.6",
@@ -265,10 +269,9 @@
    "version": "3.6.5"
   },
   "tags": [
-   "fractions",
-   "square roots",
-   "sequence",
-   "periodic"
+   "diophantine",
+   "equation",
+   "pell's equation"
   ]
  },
  "nbformat": 4,
diff --git a/ipython/html/index.html b/ipython/html/index.html
index 077d06d..4e760a0 100644
--- a/ipython/html/index.html
+++ b/ipython/html/index.html
@@ -1042,16 +1042,14 @@
                 <tr>
                 
                   <td><a href="EulerProblem066.html">Problem 066</a></td>
-                  <td>Tue, 22 Jan 2019, 05:10</td>
+                  <td>Mon, 28 Jan 2019, 21:08</td>
                   <td>
                   
-                    <kbd>fractions</kbd>
+                    <kbd>diophantine</kbd>
                   
-                    <kbd>square roots</kbd>
+                    <kbd>equation</kbd>
                   
-                    <kbd>sequence</kbd>
-                  
-                    <kbd>periodic</kbd>
+                    <kbd>pell's equation</kbd>
                   
                   </td>
                 </tr>