Logic Masters Deutschland e.V.

This is my second puzzle based on the idea of alternating sums and arrows. If you like it, check out Alternating Universe. For a hint for the break-in look under the puzzle.

Have fun and be creative!

• Normal arrow sudoku rules apply (normal sudoku rules apply and numbers on an arrow sum up to the number in the attached circle).
• Digits outside the grid show the alternating sum in that row/column. The alternating sum is calculated by alternatingly adding and subtracting digits (so if you have 123 456 789 in a row - in that order - its alternating sum is 1-2+3-4+5-6+7-8+9 = 5)
• Digits can not repeat within a cage.
• In cages the digital root of the cage total is given as a hint in the top left corner (so if you have a cage with 3, 4 and 8 than the hint will be 6 since 3+4+8 = 15 and 1+5 = 6).
• A number in a circle between 4 cells says that diagonally adjacent cells have a difference of at least that number (so if there is a 4 between r1c1, r1c2, r2c2 and r2c1, then r1c1 and r2c2 as well as r1c2 and r2c1 have a difference of at least 4).

Hint: Find out the sum of the cells in the even rows even columns and the cells in the odd rows odd columns.