Logic Masters Deutschland e.V.

General Rules: 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.

Binary Numbers: Cells linked by a straight blue line form a binary number. Each digit contributes to the binary number according to its parity: if the digit is even, it represents a 0 bit; if it’s odd, a 1 bit. Binary numbers are read from left to right or from top to bottom. So 8-5-4-7 is even-odd-even-odd or 0101 for a value of 5. It is not possible to have a binary number that is only made of even digits and would add up to 0.

Note that the binary numbers have different lengths.

Binary Sums: Each number on the left or on the top of the grid is the sum of the values of the binary numbers present in this row or this column.

Sums within the Binary Numbers: In each of the binary numbers, it is possible to choose one to six digits that add up to the value of the number. For instance, on the right are three valid groups of cells for the 12 binary number.

Additionally, if the binary number has a value between 1 and 9, it must contain the corresponding digit.