Normal sudoku rules apply. Digits in a cage must not repeat and must sum to the number in the top left corner of the cage. Draw a one-cell-wide loop of orthogonally connected cells. The loop may not touch itself, not even diagonally. The loop must enter at least one cell of each cage. Numbers on the loop count as double their value when calculating cage sums. For example, a 2-cell cage summing to 10 may contain a 2 on the loop and a 6 not on the loop. The loop acts as a German Whispers line (i.e., adjacent digits on the loop must have a difference of at least 5). The original, undoubled value of the digit is always used for the purposes of the German Whispers constraint.