Draw one closed loop

Slitherlink

Connect the dots into a single closed loop. Each number says how many of its four sides carry a line, and the loop never branches or crosses itself.

Lines 0

Tap between two dots to draw a line; tap again for ✕ (no line), a third tap clears. A number turns red when overloaded and dims when satisfied. Corners are your friends: 0 means no lines at all, a 3 in a corner forces both outer edges.