Logic Masters Deutschland e.V.

Doughnut Sudoku rules apply- ie box five contains no digits. All other boxes each contain all the digits from one to nine as do rows 1,2,3,7,8,9 and columns 1,2,3,7,8,9.
Digits along indicated diagonals sum to total given.
Boxes 2 and 8 are 3x3 magic squares where each 3 cell row,column and diagonal adds to the same total.
Each digit apart from the number 5 can reach every other cell on the grid with its same digit in exactly six chess knight's moves.
Black dots indicate cells with 2:1 ratio - not all dots are given.
To check answer fill in box five with ones in every cell.

Solve online:Sudokupad