Figure 1
Trace every line once
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a quiet night ofOne-Stroke Sky

Trace every line between the stars in one flowing stroke, never going over a line twice. Each figure you finish becomes a constellation in your sky. No timers, no ads. Rewind whenever you like.

In 1736 Leonhard Euler asked whether you could walk across all seven bridges of Königsberg exactly once. His answer began graph theory, and it's the secret of these puzzles: count how many lines meet at each star.