Logic Masters Deutschland e.V.

Rules:

Normal Sudoku rules apply: place the digits 1-9 in every row, column, and 3x3 region.

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

3x3 region borders divide the loop into segments. Every loop segment acts as a thermometer, where digits strictly increase from one end of the segment to the other. A 3x3 region can have multiple segments, and single-cell segments inherently satisfy this constraint.

All segments have digits increase in the same direction along the loop. In other words, if you were to traverse the entire loop in one direction, you would always see digits increase in each segment or always see digits decrease in each segment. Determining which direction has digits increase is up to the solver.

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