#define NO_CATS    0
#define ONE_CAT    1
#define MULTI_CATS 2
#define SAME_CATS  3

int walk_back(struct Map_info *, int, int);
int walk_forward_and_pick_up_coords(struct Map_info *, int, int,
                                    struct line_pnts *, int *,
                                    struct line_cats *, int);
