X-Sums

What is the X-Sums rule?

X-Sums is a variant sudoku rule: clues outside the grid give the sum of the first X digits in that row or column, where X is the digit nearest the clue.

In every puzzle here the setter’s own rules text is shown beside the board, so the exact wording for the puzzle you are solving is always one glance away. All normal sudoku rules apply unless the setter says otherwise.