It is night in a small town. Its streets meet at crossings, and a lamp on a crossing lights every street that leaves it.
Click a crossing to put up a lamp (click again to take it down). A street with no lamp at either end stays dark.
Once every street is lit, you may submit — and the town council pays per lamp, so use as few as you can.
After submitting you learn how few lamps would have done, and where you stand against everyone else. You can keep tinkering and
resubmit (your best counts), but only a first submission that already uses the minimum earns the
★ blind optimum badge.
Crossings can be dragged around to untangle the map; that changes nothing but the view.
Keys: n/p next/previous town, c take all lamps down, enter submit.
lamps0
dark streets0
click a crossing: lamp up / down · drag it to move it · enter submit