Logic Masters Deutschland e.V.

Normal sudoku rules apply.

X-sums: Clues outside the grid are X-sums, some of which must be deduced by the solver. An X-sum clue gives the sum of the first N digits in that row or column, where N is the first digit seen by the clue.

Modular Lines: Lines are Modular Lines. Every set of three sequential digits along a line must contain a complete set of residues modulo 3, i.e. inside the grid, this would be one digit from {1,4,7}, one from {2,5,8}, and one from {3,6,9}. Digits may repeat on a line if allowed by other rules. Modular lines of length 2 must contain elements from different classes. (Outside the grid, numbers larger than 9 are allowed, but the relationship between the residue classes is the same.)

For automatic answer check, enter each digit in the grid, as well as all of the x-sums clues on lines outside the grid, in red, blue, or green.

Solve online with Penpa+.