diff --git a/15_autoencoders.ipynb b/15_autoencoders.ipynb
index e108884..1d778bf 100644
--- a/15_autoencoders.ipynb
+++ b/15_autoencoders.ipynb
@@ -610,7 +610,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "There are many ways to train one Autoencoder at a time. The first approach it to train each Autoencoder using a different graph, then we create the Stacked Autoencoder by simply initializing it with the weights and biases copied from these Autoencoders."
+    "There are many ways to train one Autoencoder at a time. The first approach is to train each Autoencoder using a different graph, then we create the Stacked Autoencoder by simply initializing it with the weights and biases copied from these Autoencoders."
    ]
   },
   {
@@ -2360,7 +2360,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.6.4"
+   "version": "3.5.5"
   },
   "nav_menu": {
    "height": "381px",