The origin of this puzzle is not known.
Puzzle and Goal
An unsolved puzzle consists of a square grid. Walls have been marked off to indicate a single path through all cells in the grid; a circle indicates the start of the path.
The goal is to place numbers in some of the cells to satisfy the rules.
The solved grid must satisfy the following conditions:
Each number that appears in the puzzle must appear exactly once in each rank.
Numbers must appear in order traveling along the path (1-2-3-1-2-3, and so on).