struct treeNode
{
	int data;
	struct treeNode *left, *right:
};

//This recursive function will find the kth smallest node in a binary search tree
int rank(struct treeNode*ptr, int k)
{
	int counter = 0;

	if(ptr == NULL)
	   return NULL;

	while(counter != k)
		//In order traversal
		rank(ptr->left);
		rank(ptr->root);
		rank(ptr->right);
		counter++;
	}

	return k;
}