Kara walks horizontally (or vertically) forth and back


There have to be at least 3 fields between the trees: 1 for the starting position of Kara and 2 for a transition. The distance between the trees has to be odd, since Kara takes two steps in each state transition. This way, the solution only needs two states. Vertically there has to be at least one empty row in between the trees.

World size: The smallest possible world is therefore 5 x 3 fields: