In a Kakuro puzzle, the digits 1–9 are used to fill the white squares without repetition in an entry. The sum of the numbers in each entry equals the clue (in pink). The clue for a column entry is a number above the column in the lower half of a pink square; the clue for a row is a number to the left of the row in the upper half of a pink square. For the clue "4" and a line of two white squares, the answer could be "1 3" or "3 1", but not "2 2" because that would repeat the "2".