Author: GD
Place two circles in every row/column. Cells with circles should not touch each other, even diagonally. Numbers outside the grid indicate the number of cells between the circles in that row or column.
Grid control: Click the mouse button at the selected cell to set/remove a circle. 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.