diff --git a/core/structs.ipynb b/core/structs.ipynb
index b418f86..a55d6a6 100644
--- a/core/structs.ipynb
+++ b/core/structs.ipynb
@@ -1,7 +1,7 @@
 {
  "metadata": {
   "name": "",
-  "signature": "sha256:4ef710b63179ecbbd57fefec7193c3b8807f6bf54626f98718c1f52b6e2a0eca"
+  "signature": "sha256:ff550086599556097647343c3017be187c43704edd375629f4d14fb5a4c12859"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -15,6 +15,15 @@
       "# Data Structures"
      ]
     },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "* tuple\n",
+      "* list\n",
+      "* dict"
+     ]
+    },
     {
      "cell_type": "markdown",
      "metadata": {},