This puzzle was invented by Inaba Naoki.
Puzzle and Goal
An unsolved puzzle consists of a rectangular grid. Some cells contain circles.
The goal is to color some of the cells black.
The solved grid must satisfy the following conditions:
Black cells may not touch orthogonally, and may not be in circled cells.
The minimal path between any two circled cells must turn at least twice.
The white cells must form an orthogonally contiguous area.