My logic may well be flawed. ??? ¥
If for the weighing of 2x9's...1 balaces (cfc not in these 18)...1 unbalanced (cfc is in the only 9 not in the balanced set , and as i know which side of the scale it is/was on, i know h or l too.
From 9 knowing h/l, can solve in two balances.
Where have i gone wrong?
This is a fun puzzle.