Logic Masters Deutschland e.V.

Rules: X-Sum/XV variant
1. (Normal sudoku) Fill the grid with digits from 1-9 such that no digits repeat in each row/column/region.
2. (XV) If an edge is marked with an X, then the sum of the digits adjacent to the edge must be 10.
3. (X-sum) Numbers outside the grid represent the sum of the first x digits in that direction, where x is the digit in the first cell of that direction.
4. Furthermore, shade some cells to form a snake. The digit in the center of every region indicates how many cells are shaded in that region. A snake is an orthogonally connected path that never touches itself, not even diagonally.
5. The snake can be divided into disjoint segments such that the sums of each segment in order form an arithmetic sequence. There may be multiple ways to segment the snake.



You can solve the puzzle here.

This is one of 12 disjoint puzzles I made this year with varying styles/difficulties themed around snakes and 2025.
Enjoy!