Normal sudoku rules apply ie Place the digits 1 to 9 once each in every row, column, and 3x3 box. Coordinate Arrows: Digits on an arrow spell out the coordinates for the digit that is their sum. The row number is written on the start of the arrow, the column number is written on the arrow tip. For example, read from shaft to tip, if an arrow contained the digits 14 then there must be a 5 in r1c4. All the arrows must correspond to different coordinates. Digits may repeat on an arrow if allowed by other rules