diff --git a/problems/016_problem/016_problem.ipynb b/problems/016_problem/016_problem.ipynb
index fa2d2af..88e4dd0 100644
--- a/problems/016_problem/016_problem.ipynb
+++ b/problems/016_problem/016_problem.ipynb
@@ -25,7 +25,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": 13,
    "metadata": {},
    "outputs": [
     {
@@ -43,29 +43,43 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 11,
+   "execution_count": 12,
    "metadata": {},
    "outputs": [
     {
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "<class 'str'>\n",
       "['1', '0', '7', '1', '5', '0', '8', '6', '0', '7', '1', '8', '6', '2', '6', '7', '3', '2', '0', '9', '4', '8', '4', '2', '5', '0', '4', '9', '0', '6', '0', '0', '0', '1', '8', '1', '0', '5', '6', '1', '4', '0', '4', '8', '1', '1', '7', '0', '5', '5', '3', '3', '6', '0', '7', '4', '4', '3', '7', '5', '0', '3', '8', '8', '3', '7', '0', '3', '5', '1', '0', '5', '1', '1', '2', '4', '9', '3', '6', '1', '2', '2', '4', '9', '3', '1', '9', '8', '3', '7', '8', '8', '1', '5', '6', '9', '5', '8', '5', '8', '1', '2', '7', '5', '9', '4', '6', '7', '2', '9', '1', '7', '5', '5', '3', '1', '4', '6', '8', '2', '5', '1', '8', '7', '1', '4', '5', '2', '8', '5', '6', '9', '2', '3', '1', '4', '0', '4', '3', '5', '9', '8', '4', '5', '7', '7', '5', '7', '4', '6', '9', '8', '5', '7', '4', '8', '0', '3', '9', '3', '4', '5', '6', '7', '7', '7', '4', '8', '2', '4', '2', '3', '0', '9', '8', '5', '4', '2', '1', '0', '7', '4', '6', '0', '5', '0', '6', '2', '3', '7', '1', '1', '4', '1', '8', '7', '7', '9', '5', '4', '1', '8', '2', '1', '5', '3', '0', '4', '6', '4', '7', '4', '9', '8', '3', '5', '8', '1', '9', '4', '1', '2', '6', '7', '3', '9', '8', '7', '6', '7', '5', '5', '9', '1', '6', '5', '5', '4', '3', '9', '4', '6', '0', '7', '7', '0', '6', '2', '9', '1', '4', '5', '7', '1', '1', '9', '6', '4', '7', '7', '6', '8', '6', '5', '4', '2', '1', '6', '7', '6', '6', '0', '4', '2', '9', '8', '3', '1', '6', '5', '2', '6', '2', '4', '3', '8', '6', '8', '3', '7', '2', '0', '5', '6', '6', '8', '0', '6', '9', '3', '7', '6']\n"
      ]
     }
    ],
    "source": [
-    "sum=0\n",
-    "sum+=big_integer%10\n",
-    "\n",
     "str_big_integer=str(big_integer)\n",
-    "print(type(str_big_integer))\n",
-    "\n",
     "list_big_integer=list(str_big_integer)\n",
     "print(list_big_integer)"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "1366\n"
+     ]
+    }
+   ],
+   "source": [
+    "sum=0\n",
+    "for digit in list_big_integer:\n",
+    "    sum+=int(digit)\n",
+    "print(sum)"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,