????????
      ----------
UFNNF ) FYYYYXTH
       -UFNNF
        =====
        QYCCNX
       - UFNNF
        ======
         HFHFPT
        -HUPXCH
         ======
          QCNRPH
         -QPCRUC
          ======
          ??????

base: 12
symbols: CFHNPQRTUWXY
missing: W
difficulty: hard