... Well, this is still going to be a difficult challenge. He has the hint, but he needs the Law; whatever it is can't be simple addition, because at one point he tossed a hundred billion in. Each slot may still mean something different, and he has such a tiny, frustrating window to tell useful things from his information!
Still, things may be simple. 3,5,7 again?
(NO, instantly.)
3,5,7 again continues to be no? (NO, instantly.)
Excellent. Then he's going to check this again just because Keltham is a sadist. 3,5,7? (NO.)
Excellent. Then... is it really just that simple? His guess, this time, is that anything you've tried before gets a 'no' and anything else gets a 'yes'.
CORRECT.
... He cannot believe it took him this long to get it, but yes, he is feeling... joy, at finally mastering a difficult art, at taking an absurdly complicated thing-in-the-world, and studying it, and reducing it down to something so simple, that he couldn't believe it took him so long to understand it. Through pain, to strength. Great is Asmodeus, Lord of All.
(And Alexandre will let a tiny bit of the happiness he is feeling leak through, since alterAlexandre would not hide his expressions as well as trueAlexandre. Just a little.)