Balance Loop is a logic puzzle created by Prasanna Seshadri (India). A rectangular or square grid contains black and white circles in some cells. The aim is to draw a single continuous non-intersecting loop that visits all cells with circles. Loop segments extending from a white circle are of equal length, while the loop segments extending from a black circle are not. If a cirlce contains a number, it indicates the sum of the loop segment lengths on both sides of the circle before turning.
Cross+A can solve puzzles from 3 x 3 to 30 x 30.