Logic Masters Deutschland e.V.

Normal sudoku rules apply.

Digits along an arrow sum to the digit in that arrow's circle.

Digits in yellow circles indicate how many yellow circles contain that digit.

Additionally, digits in yellow circles must be grouped into pairs. Each pair form opposite corners of a square (whose sides are aligned with the grid), one other corner of which must be the sum of the pair. (Eg if r4c7 and r7c4 were a pair, the sum could go in r4c4 or r7c7.)

Different pairs cannot use the same square for their sum. (Eg if r3c4 and r4c3 were also a pair, then r4c4 could be used for the sum of this pair OR the sum of the previous pair, but NOT both.)

It is possible that the sum for one pair of circles may itself be in a cell which is already circled. Which circles are paired and where their sums go must be determined by the solver.

Play online (Sudoku Pad)

Cracking the Cryptic solve