struct node {
	struct node *left;
	struct node *right;
	int value;
	};
struct node *head;
int v1;

#define PASS2(bit) \
	n2 = n1->left; \
	right = n1->right; \
    if (value & (1<<bit)) \
        n2 = right; \
	n1 = n2->left; \
	right = n2->right; \
	if (value & (2<<bit)) \
		n1 = right;

main()
{
int j;
unsigned int value = v1;
struct node *n1 = head, *n2, *right;
for (j=0; j<4; ++j) {
	PASS2(0)
	PASS2(2)
	PASS2(4)
	PASS2(6)
	value >>= 8;
	}
printf("result=%p\n", n1);
}