????????
      +---------
LNUMC | XUMFFNXY
       -LNUMC
        =====
        QJLWNN
       -QQCWWY
        ======
         QQMRFX
        -FLUYWC
         ======
          LLWWLY
         -LFJLQY
          ======
          ??????

base: 12
letters: CFJLMNQRUWXY
difficulty: medium