Normal sudoku rules apply. Draw a one-cell wide snake, which starts in Box 5 and ends in Box 9, that moves orthogonally through the center of cells. The snake is not allowed to branch, intersect with itself or touch itself, even diagonally. Cells that are orthogonally adjacent along the snake have to contain consecutive digits. Within each box, the box number is part of the snake. Cells separated by a black dot contain digits that are in a 1:2 ratio. All black dots are given.