Logic Masters Deutschland e.V.

Click on the image to play (on SudokuPad)

Rules:

Normal Sudoku rules apply.

Modular Summation Arrows: An arrow cell with digit N sees at least N cells in each of the indicated directions, and the digits in all those cells (exact total count: number-of-arrows × N) sum to a number whose last digit (unit digit) is N. For example, a cell with two arrows and digit 3 may point to the digits 123 and 458 respectively, which together sum to 23, ending in 3.