### Chain Sudoku

**Chain Sudoku** (also known as *"Strimko"*) consists of a group of circles arranged in a square grid and containing given clues in various places. The object is to fill all empty circles so that the digits appear exactly once in each row, column and chain.

The program can solve and create puzzles from **4 x 4** to **9 x 9**. Task files have the extension *.**CHS**.