4 ms·

now try when the buttons don't all do the same thing https://www.chiark.greenend.org.uk/~sgtatham/puzzles/js/flip.html#5x5r https://www.chiark.greenend.org.uk/

• danparsonson 3y ago
  Ye gods
• creata 3y ago
  (Probably obvious, but the exact same reduction to a system of linear equations can solve this.)