7 5 2 01X 20 0 0 2 X L 0 1 1 1 R 0 X 0 X R 0 _ 5 _ R 1 0 2 X L 1 1 1 1 R 1 X 1 X R 1 _ 6 _ R 2 0 2 0 L 2 1 2 1 L 2 X 2 X L 2 > 3 > R 3 0 3 0 R 3 1 4 X L 3 X 3 X R 3 _ 6 _ R 4 0 4 0 L 4 1 4 1 L 4 X 4 X L 4 > 0 > R 1 0 1 1 1 0 1 0 0 0 _