Logic Masters Deutschland e.V.

- Normal sudoku rules apply.

- The grid is mostly covered in fog. Placing correct digits will lift the fog around the placed digit revealing more clues.

- Digits along an arrow must sum to the number in the arrow's circle. Given circles contain exactly one arrow. Given arrows do not overlap or share a cell.

- Cells separated by a black dot must contain one digit that's double the other.

- Draw a 1-cell wide snake moving orthogonally starting at r1c1 and ending at r9c9. The snake does not branch or touch itself, even diagonally. Given arrows and arrow circles are not part of the snake.

- The snake is comprised of overlapping arrow clues such that every arrow on the snake is entirely contained within the snake. Every pair of adjacent digits along the snake must have an arrow crossing between them. A circle on the snake may have one or two arrows. A circle may appear along another arrow.