Example puzzle
This is an example puzzle. You can solve it the same way as you would solve competition puzzle, but result never stored. You can reveal an answer for the puzzle by clicking "Show answer" link.
Polygraph
Author: Andrey Bogdanov
Draw a single continuous loop along the gridlines in the diagram. The numbers inside the loop indicate how many of that cell's edges are used by the path. The numbers outside the loop indicate how many of that cell's edges are not used by the path. The path cannot cross or touch itself.
Grid control: To draw a fence click at the cell edge or move mouse along the line holding the button. You can also put auxiliary marks by clicking at cells. More details about grid control are at the help page.