     ]
    },
    {
     "cell_type": "code",
     "execution_count": 4,
     "metadata": {
      "collapsed": false
     },
     "outputs": [
      {
 
</s> remove    "execution_count": 3,
 </s> add    "execution_count": 4, </s> remove    "outputs": [],
 </s> add    "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Writing height.py\n"
     ]
    }
   ],
   "execution_count": 5,
     ]
    },
    {
     "cell_type": "code",
   "execution_count": 5,
     "metadata": {
      "collapsed": false
     },
     "outputs": [
      {
keep keep keep keep replace keep keep keep keep keep
 Saved tree height challenge solution so it can be reused as a component to other related challenges. 
graphs_trees/tree_height/height_solution.ipynb