The origin of this puzzle is not known.
Puzzle and Goal
An unsolved puzzle consists of a square grid with numbers to the top and side. Two of the cells are marked.
The goal is to connect the marked cells.
The solved grid must satisfy the following conditions:
The numbers on the top and side indicate the number of black cells in the corresponding rank.
Black cells create a single path of orthogonally neighboring cells. No 2x2 regions are created, and the path does not touch itself.