????????
      +---------
XPJJG | WYFEQEYT
       -XPJJG
        =====
        NQYFFE
       -NLUFPJ
        ======
         UNMXGY
        -UJMQEQ
         ======
          UMMWPT
         -LTETFF
          ======
          ??????

base: 14
letters: EFGJLMNPQTUWXY
difficulty: hard