Logic Masters Deutschland e.V.

Normal Sudoku rules apply. Place four tetrominos in the upper grid of the following colors: red, blue, green, grey. In a tetromino, the cells are numbered from top to bottom then left to right (see example on the left). Each box of the tetromino represents the line of that color in the corresponding sudoku grid. For example, if box 3 of the blue tetromino was in the palindrome row, that means the blue line in the third grid (bottom left) is a palindrome line.
- Along whisper lines, adjacent digits must differ by at least 3.
- Along palindrome lines, cells equidistant from the middle contain the same digit
- Along renban lines, the digits in cells form a consecutive sequence (not necesarily in order)
- Along modular lines, each sequence of three cells contains one digit from each modular group (1/4, 2/5, 3/6)

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