Logic Masters Deutschland e.V.

Normal sudoku rules apply.

Japanese Sums - Clues outside the grid indicate the sums of the digits in contiguous blocks in that row/column. Cells in blocks should be shaded. Blocks must be separated by at least one unshaded cell. A '?' indicates a block with an unknown sum.

Sandwich - If a row/column has a known (non-?) clue, it acts as both a Japanese Sums clue and a Sandwich clue. Sandwich clues outside the grid indicate the sum of the digits between the 1 and the 9 in that row/column.

Disclaimer - the shaded cells do not form an image

Solve on f-puzzles