Logic Masters Deutschland e.V.

Normal Sudoku rules: Place the digits 1-9 in every row, column and box.

Renban: Every magenta line contains a set of consecutive digits in any order, without repeats.

Skyscrapers: Each cell represents a skyscraper whose height is the digit in that cell. Taller skyscrapers obscure the view of smaller ones. Clues outside the grid count how many skyscrapers can be seen in their row or column looking from the clue.