diff --git a/graphs_trees/bst_min/bst_min_challenge.ipynb b/graphs_trees/bst_min/bst_min_challenge.ipynb
index cd34d60..7531c6e 100644
--- a/graphs_trees/bst_min/bst_min_challenge.ipynb
+++ b/graphs_trees/bst_min/bst_min_challenge.ipynb
@@ -90,15 +90,10 @@
    },
    "outputs": [],
    "source": [
-    "def create_min_bst(array):\n",
-    "    # TODO: Implement me\n",
-    "    # Calls _create_min_bst\n",
-    "    pass    \n",
+    "class MinBst(object):\n",
     "\n",
-    "\n",
-    "def _create_min_bst(array, start, end):\n",
-    "    # TODO: Implement me\n",
-    "    pass"
+    "    def create_min_bst(self, array):\n",
+    "    # TODO: Implement me"
    ]
   },
   {
@@ -115,17 +110,6 @@
     "**The following unit test is expected to fail until you solve the challenge.**"
    ]
   },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": [
-    "%run ../tree_height/height.py"
-   ]
-  },
   {
    "cell_type": "code",
    "execution_count": null,
@@ -138,15 +122,24 @@
     "from nose.tools import assert_equal\n",
     "\n",
     "\n",
+    "def height(node):\n",
+    "    if node is None:\n",
+    "        return 0\n",
+    "    return 1 + max(height(node.left),\n",
+    "                   height(node.right))\n",
+    "\n",
+    "\n",
     "class TestBstMin(object):\n",
     "\n",
     "    def test_bst_min(self):\n",
+    "        min_bst = MinBst()\n",
     "        array = [0, 1, 2, 3, 4, 5, 6]\n",
-    "        root = create_min_bst(array)\n",
+    "        root = min_bst.create_min_bst(array)\n",
     "        assert_equal(height(root), 3)\n",
     "\n",
+    "        min_bst = MinBst()\n",
     "        array = [0, 1, 2, 3, 4, 5, 6, 7]\n",
-    "        root = create_min_bst(array)\n",
+    "        root = min_bst.create_min_bst(array)\n",
     "        assert_equal(height(root), 4)\n",
     "\n",
     "        print('Success: test_bst_min')\n",
diff --git a/graphs_trees/bst_min/bst_min_solution.ipynb b/graphs_trees/bst_min/bst_min_solution.ipynb
index c9186dd..6e28364 100644
--- a/graphs_trees/bst_min/bst_min_solution.ipynb
+++ b/graphs_trees/bst_min/bst_min_solution.ipynb
@@ -102,20 +102,21 @@
     "from __future__ import division\n",
     "\n",
     "\n",
-    "def create_min_bst(array):\n",
-    "    if array is None:\n",
-    "        return\n",
-    "    return _create_min_bst(array, 0, len(array)-1)\n",
+    "class MinBst(object):\n",
     "\n",
+    "    def create_min_bst(self, array):\n",
+    "        if array is None:\n",
+    "            return\n",
+    "        return self._create_min_bst(array, 0, len(array)-1)\n",
     "\n",
-    "def _create_min_bst(array, start, end):\n",
-    "    if end < start:\n",
-    "        return None\n",
-    "    mid = (start + end) // 2\n",
-    "    node = Node(array[mid])\n",
-    "    node.left = _create_min_bst(array, start, mid-1)\n",
-    "    node.right = _create_min_bst(array, mid+1, end)\n",
-    "    return node"
+    "    def _create_min_bst(self, array, start, end):\n",
+    "        if end < start:\n",
+    "            return None\n",
+    "        mid = (start + end) // 2\n",
+    "        node = Node(array[mid])\n",
+    "        node.left = self._create_min_bst(array, start, mid-1)\n",
+    "        node.right = self._create_min_bst(array, mid+1, end)\n",
+    "        return node"
    ]
   },
   {
@@ -128,17 +129,6 @@
   {
    "cell_type": "code",
    "execution_count": 3,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": [
-    "%run ../tree_height/height.py"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 4,
    "metadata": {
     "collapsed": false
    },
@@ -156,15 +146,24 @@
     "from nose.tools import assert_equal\n",
     "\n",
     "\n",
+    "def height(node):\n",
+    "    if node is None:\n",
+    "        return 0\n",
+    "    return 1 + max(height(node.left),\n",
+    "                   height(node.right))\n",
+    "\n",
+    "\n",
     "class TestBstMin(object):\n",
     "\n",
     "    def test_bst_min(self):\n",
+    "        min_bst = MinBst()\n",
     "        array = [0, 1, 2, 3, 4, 5, 6]\n",
-    "        root = create_min_bst(array)\n",
+    "        root = min_bst.create_min_bst(array)\n",
     "        assert_equal(height(root), 3)\n",
     "\n",
+    "        min_bst = MinBst()\n",
     "        array = [0, 1, 2, 3, 4, 5, 6, 7]\n",
-    "        root = create_min_bst(array)\n",
+    "        root = min_bst.create_min_bst(array)\n",
     "        assert_equal(height(root), 4)\n",
     "\n",
     "        print('Success: test_bst_min')\n",
@@ -181,7 +180,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 4,
    "metadata": {
     "collapsed": false
    },
diff --git a/graphs_trees/bst_min/test_bst_min.py b/graphs_trees/bst_min/test_bst_min.py
index eb1e510..963ae70 100644
--- a/graphs_trees/bst_min/test_bst_min.py
+++ b/graphs_trees/bst_min/test_bst_min.py
@@ -1,15 +1,24 @@
 from nose.tools import assert_equal
 
 
+def height(node):
+    if node is None:
+        return 0
+    return 1 + max(height(node.left),
+                   height(node.right))
+
+
 class TestBstMin(object):
 
     def test_bst_min(self):
+        min_bst = MinBst()
         array = [0, 1, 2, 3, 4, 5, 6]
-        root = create_min_bst(array)
+        root = min_bst.create_min_bst(array)
         assert_equal(height(root), 3)
 
+        min_bst = MinBst()
         array = [0, 1, 2, 3, 4, 5, 6, 7]
-        root = create_min_bst(array)
+        root = min_bst.create_min_bst(array)
         assert_equal(height(root), 4)
 
         print('Success: test_bst_min')