Author: Vladimir Portugalov
Paint all cells of the grid into two different colors. Numbers on the top and at the left show the maximum length of block of the cells of dark color in the corresponding row or column. Numbers at the right and in the bottom show the maximum length of blocks of the cells of light color.
Grid control: Click the mouse button at the selected cell to change the color of the cell. You can use mouse dragging to copy content from one cell to another. More details about grid control are at the help page.