In each NxN grid, place the digits 1-N once in every row, column and box; in the slanted 6x6 grid, digits should be entered only in the middle of cells. A digit may not appear in the same position in multiple 4x4 grids. Each arrow contains a 2-digit number, with the 10s digit on the shaft and the 1s digit on the head; the number on an arrow gives the sum of the first X digits seen in a straight line in the indicated direction, where X is the first digit seen. Arrows only see cells that contain digits, i.e. blank spaces, such as those not belonging to any grid, are not seen.