Logic Masters Deutschland e.V.

Place a digit from 1 to 9 into each cell of the grid so that every row, column and outlined 3x3 region contains each digit exactly once.

Each of the 9 regions is associated with one digit, shown as its background. Inside a region, if two neighboring digits – orthogonally or diagonally – are the coordinates in the grid of the associated digit, a line must join them. In this puzzle, the coordinates (1,1) indicate the top left corner of the grid.

Example

Since 2 and 6 are joined by a line in the 1 region, one or two of the cells marked by a star must contain a 1.

Since 6 and 8 are neighbors in the 1 region but are not joined by a line, the cells marked by a cross cannot contain a 1.

Penpa-Edit link for this puzzle to play it online.