Logic Masters Deutschland e.V.

• Normal sudoku rules apply.
• Entropy. Each 2x2 box in a grid has contain low digit {1,2,3}, middle digit {4,5,6} and high digit {7,8,9}.

If you can use a classic sudoku trick related to symmetry, then you will get a sudoku with a difficulty of 2 stars. And if not, then you will get an even more interesting sudoku with a difficulty of 4 stars. Dear experts, write in the comments whether it is correct to use this trick in sudoku with entropy.

SudokuPad link