struct TreeNode
{
   int value;
   TreeNode *leftChild;
   TreeNode *rightChild;
};

struct Tree
{
    TreeNode *root;
};

TreeNode **search(TreeNode *&currentNode, int x)
{
    if (currentNode == NULL)
        return NULL;
    if (x == currentNode->value)
        return &currentNode;
    if (x < currentNode->value)
        return search(currentNode->leftChild, x);
    else
        return search(currentNode->rightChild, x);
}