Logic Masters Deutschland e.V.

Normal Sudoku rules apply

Digit in a green cell are friendly. A friendly cell has a value identical to its row-, column- or box-number, counted in the standard way.

Question marks outside the grid are Sandwich clues, which have to be positive integers (not 0) and are either a single digit clue(?), or double digits (??). Sandwiches make a valid thermo with their crusts and digits, seen from the direction of the clue (13569 for instance).

F-puzzles

CTC-app