????????
      +---------
CRFGF | EGQMCQYR
       -CRFGF
        =====
        WCUMEQ
       -WMXFEX
        ======
         YXRXQY
        -MEWCQX
         ======
          YUTXYR
         -MEWCQX
          ======
          ??????

base: 12
letters: CEFGMQRTUWXY
difficulty: medium