Author: Andrey Bogdanov
Place a number into each cell so that each region contains an orthogonally-connected chain of consecutive numbers from 1 to N, where N is the number of cells in the region. Numbers of the same value may not touch one another, not even diagonally.
Grid control: Click at a cell reveals the value chooser. Click at the selected value changes the state of the cell. More details about grid control are at the help page.