Logic Masters Deutschland e.V.

Place the digits 1 to 9 in every row, column and 3x3 standard block. The following three rules must be satisfied:

*** Cells connected with a chess-knight move could not contain same digits.

*** There exist no neighbouring cells with consecutive digits.

*** Two same numbers can not touch each other diagonally.

Besides grey painted cells form renban groups. These groups must hold consecutive digits, in any order.