Gokigen Naname (from Japanese, literally "to be in a bad mood"; also known as "Slalom", "Slant") is a logic puzzle invented by Nikoli. It is played on a rectangular or square grid. Circles with digits from 0 to 4 may be situated on intersections of lines inside the grid. The aim is to fill in a diagonal line in every cell. The number in each circle equals the number of lines extending from that circle. The diagonal lines must not form a closed loop.
Cross+A can solve puzzles from 4 x 4 to 40 x 40.