#include <stdio.h>

#define TRUE 1
#define FALSE 0

typedef int BOOLEAN;
typedef int ETYPE;

typedef struct NODE *TREE;
struct NODE {
	ETYPE element;
	TREE leftChild, rightChild;
};

TREE insert(ETYPE x, TREE T)
{
	if (T == NULL) {
		T = (TREE) malloc(sizeof(struct NODE));
		T->element = x;
		T->leftChild = NULL;
		T->rightChild = NULL;
	}
	else if (x < T->element)
		T->leftChild = insert(x, T->leftChild);
	else if (x > T->element)
		T->rightChild = insert(x, T->rightChild);
	return T;
}