Logic Masters Deutschland e.V.

Thanks to the CtC discord for helping validate!

Normal sudoku rules apply.

Build a 1 cell width loop that travels orthogonally from cell to cell and never touches itself, even diagonally.

All friendly cells must be on the loop. Non-friendly cells may be on the loop. A cell is friendly if its digit matches its row, column, or box number.

No cell is allowed to be friendly in more than one way. For example, r2c4 cannot be a 2 because it would be friendly by both its row and box.

Cells separated by a white dot are consecutive. Not all possible dots are given.

Click on the image to play