XQL
      +--------
XNHUJ | RXHHHXT
       -XNHUJ
        =====
        XXNQJX
       -XFLLFX
        ======
         XJNJFT
        -XJLFUR
         ======
           RXJJ

base: 11
letters: EFHJLNQRTUX
difficulty: medium
missing: E