Logic Masters Deutschland e.V.

Rules:

Normal Sudoku rules apply.

Draw a one-cell-wide loop of orthogonally connected cells. The loop may not touch itself, not even diagonally.

-- All circles must be on the loop. The digit in a circle gives the number of cells in the (up to) 9 surrounding cells, including itself, that are not on the loop.

-- All squares must not be on the loop. The digit in a square gives the number of cells in the (up to) 9 surrounding cells, including itself, that are on the loop.

-- The loop acts as a German Whispers line (i.e., adjacent digits on the loop must have a difference of at least 5).