????????
      +---------
FYWTL | MWTRLMRW
       -FYWTL
        =====
        WCFFLM
       -WMWRRL
        ======
         JLFJMR
        - MRTJL
         ======
          WFTTRW
         -WWCMFL
          ======
          ??????

base: 9
letters: CFJLMRTWY
difficulty: intermediate