if we mark the dots 1 - 9, by starting with the top left as 1 and the top right as 3, and the bottom left as 7 tyhen the bottom right would be 9. the line will go: 1-4-7-X-8-6-X-3-2-1-5-9
mind you, the "X" stands for the pencils moving outside the "box" if you understand my meaning.