Normal sudoku rules apply. Digits along the orange line must be broken into one or more contiguous groups of cells that each sum to ten. Such groups cannot overlap. Digits may repeat within such sums if allowed by other rules. For example, 513173 is a valid fill for a length 6 line, because it can be broken into 5131 and 73, each of which sum to 10. Digits along an arrow sum to the digit in that arrow’s circle.