????????
      +---------
RMTTM | MEEEECQJ
       -RMTTM
        =====
        WEFFTC
       - RMTTM
        ======
         JMJMGQ
        -JRGCFJ
         ======
          WFTYGJ
         -WGFYRF
          ======
          ??????

base: 12
letters: CEFGJMNQRTWY
missing: N
difficulty: hard