Logic Masters Deutschland e.V.

• Basic sudoku rules - Enter numbers from 1 to 9 into the diagram, such that in every row, every column and every bold bordered area every digit appears exactly once.
• Thermometer chains - The gray paths contain thermometers. The digit in the white circle indicate how many thermometers are in that path. All the cells in the paths are part of a thermometer. The minimal length of a thermometer is 2. The start points (bulbs) and the directions of the thermometers are unknown, but the thermometer on a path share the same direction on the path (building a clockwise or counter clockwise round trip).

(Link to Penpa)