Automatic code bridge

Ever wanted a bridge that needed a combo? Not just one that needs a combo and the other switches actually do nothing? Well look no further! In this map you will see a bridge with a code involving three switches and a button. Put in the right code and Voila! A cobble stone bridge magically appears to let you cross the lava gorge. Flip any wrong switches down though and the entire circuit is cancelled out! As a fun activity, you can try to crack the code! But if you would rather see it in action, just break the sandstone under the switch/button. If there is a red-stone torch there that is one of the levers.

Note: The bridge will have to be reset after each use (There is a repeating circuit under the sandstone in front of the levers/buttons. This powers the piston. If you don't reset it, it will just not turn off) And back wiring is exposed (In case you want to see how I did it.