I've been suffering for two days, I can't pick up the code for the elevator in the library, how to go through it?? I started playing a light, pleasant, relaxing puzzle game, and it turned into a tough brainstorm, author, why do you hate us so much?? I talked to each girl, tried all the codes that were offered there, 3 codes each... I tried on each option "let's think together" the elevator is still not available well, at least I did not forget to save before I start to solve it... So what is the algorithm of actions for finding a code??? Because the options that I see do not work.
Without spoiling it (or trying not to), I tried all the combos the girls suggested, then went back to the elevator one last time, and the character and girl decided one one last try, and it worked. I then loaded the previous save, immediately grabbed the levers in that order, and it worked.
So after trying all the suggestions, see if the girl by the levers and your character can make a final decision.