9-7+6-9=-1 has nothing to do with solving this. You can brute force it early, but the game's intent is have you open it during your return trip to the embassy to pick up relic #7 (which is where it gives you the L R R R hint).

To simplify so you don't need to watch the video:

Left button
Right button x 3

Thanks

Thanks.

very nice, thanks! :)

coolio

Спасибо. Сделал сам, но сначала застрял на этом. Довольно таки неочевидная загадка.

спасибо!