????????
      +---------
QPWEN | PUGWPJRE
       -PQUMW
        =====
         RGPHJ
        -QPWEN
         =====
         HWXQMR
        -HQNUGX
         ======
          GLLNWE
         -GQPURE
          ======
          ??????

base: 14
letters: EFGHJLMNPQRUWX
difficulty: hard
missing: F