Across The River

This is a plank puzzle game in which the goal is to cross a swamp or a river filled with tree stumps too far apart to jump between. You can pick up and carry a plonk provided you have access to one end. You can only pick up and carry one plank at a time. Planks must be supported both ends, and must be an exact fit. You cannot jump between stumps or planks. You cannot move a plank if you are already carrying one. Planks cannot be used diagonaly, only north-south or east-west. Planks cannot support other planks, and cannot be stacked. Planks cannot bridge intermediate stumps or planks.