The puzzle below is a current daily puzzle. This puzzle is competitive - you have to register to solve it and participate in the daily competition. To register click Login link in the top right corner.
You can use the scores page to see the results of other competitors for this puzzle.
All the puzzles from the previous days are available at our archive page. Puzzles which are older than 5 days do not affect the score table and can be attempted without registration.
Author: Andrey Bogdanov
Shade some cells in the grid. Numbers outside show the number of cells shaded in the corresponding row or column. All nodes where shaded cells form the chess pattern are shown.
Grid control: Click the mouse button at the selected cell to change the color of the cell. Second click will put auxiliary cross sign, which doesn't affect correctness of the solution, but helps visually. You can also drag the content of one cell to another with the mouse. More details about grid control are at the help page.