Logic Masters Deutschland e.V.

Divide the grid into regions, each consisting of nine orthogonally connected cells. Each row, column and region must contain the digits 1 to 9 once each.

A circled digit in a cell indicates the sum of the lengths of all region borders of its own region encountered along straight lines through the cell’s edges where a border runs, stopping when a border turns. Note that the region borders on the edge of the grid count toward this total. There is no negative constraint (all possible circles are not given).

Here is a 6x6 example for illustration, with a link for solving online:



Links to the main puzzle for solving online: Sudokupad or Penpa plus

Have fun! :)