So, now things stand clearer: From (4,5,8) you have to come to zero, and now you can find out a route. Obviously, the shortest route is a straight line, but maybe the configurations, the situations stand in such a way that a straight line is not even possible, so you figure out some other route, whatever it is. The thing is that now you know that you have to move from (4,5,8) to (0,0,0).
