Hiroimono

Hiroimono ("Goishi Hiroi"; from Japanese, literally "things picked up") is a logic puzzle invented by Nikoli. The grid contains circles ("stones") placed at some grid points. The task is to move along the grid lines and collect all the stones (number them in the order in which you pick them up) according to the following rules:

• Start at any stone.
• When a stone is encountered, it is picked up.
• When a stone is picked up, the direction can be changed.
• It is not allowed to reverse the direction.

Cross+A can solve puzzles from 3 x 3 to 30 x 30.