????????
      +---------
FRGXT | HYPGXHGH
       -XLMFQ
        =====
        FYTPHH
       -FJYMYX
        ======
          QNYFG
         -XLMFQ
          =====
          UTPHNH
         -UFNPXN
          ======
          ??????

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: hard
missing: W