string AlienFamilyTree::lowest_common_ancestor(NodePtr root, string name1,
                                            string name2)
{
    if(root == NULL)
    {
        return "";
    }

    if(is_descendant(root->data, name1) && is_descendant(root->data, name2))
    {
        string a = lowest_common_ancestor(root->left, name1, name2),
               b = lowest_common_ancestor(root->right, name1, name2);
    if(a == "" && b=="") { // This is the lowest common ancestor
             return root->data;
        } else if (a != "") { // The left subtree contained the lowest common ancestor
             return a;
        } else if (b != "" { // The right subtree contained the lowest common ancestor
             return b;
        } else { // WHAT THE HELL????????????????????????????? } // I have no idea
    } else { // This subtree does not contain both children
    return "";
    }
}