typedef struct node_t {
	struct node_t *next;
	struct node_t *prev;
	void *data;
} NODE;
typedef struct list_t {
	NODE *head;
	NODE *tail;
	int size;
} LIST;
NODE *NodeNew(void *data);
LIST *ListNew(void);
void AddFirst(LIST *list, void *data);
void AddLast(LIST *list, void *data);
void *RemoveFirst(LIST *list);
void *RemoveLast(LIST *list);
int ListSize();