Logic Masters Deutschland e.V.

This puzzle is in the same vein as my previous puzzle Pointing Out Entropy.

Rules:

Normal Sudoku rules apply.

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

The loop acts as a modular line. Each set of three adjacent digits along the loop must be one each from the sets [147], [258], and [369].

Digit in cells with arrows count how many loop cells are in the indicated direction (not including the cell itself).