Logic Masters Deutschland e.V.

Sudoku: Normal Sudoku rules apply.

Whisper Loop: Draw a one-cell-wide loop of orthogonally connected cells. The loop can't touch itself, not even diagonally. Each adjacent digit along the loop differs by at least 5.

Arrowed Loop: A digit on an arrow indicates how many loop cells are in each indicated direction, not including the cell itself.

Arrowed Skyscrapers: In addition, each digit in the grid represents the height of a building in its cell. Taller buildings obstruct the view of shorter ones behind them. Clues on an arrow give the number of buildings visible from that vantage point in each indicated direction, not including the cell itself.

SudokuPad link