Logic Masters Deutschland e.V.

Normal sudoku rules apply.

Draw a single orthogonal connected non-intersecting loop which passes through every box in the grid. All circles are part of the loop and display the number of cells on the loop in the 3x3 area around (and including) the cell. While the loop is in one box, all cells on the line must have the same residue mod 3 (e.g. 1,4,7). This residue must switch when the line leaves the box. If a line leaves and then re-enters a box, it need not have the same residue.

Normal kropki rules apply - digits with a white dot between them are consecutive. There is no negative constraint.

Happy solving!