????????
      +---------
WNQFN | XFRLNGMW
       -WNQFN
        =====
        GRFUTG
       -GUFWGC
        ======
         GTLUUM
        - WNQFN
         ======
          FXFQCW
         -FFLMQR
          ======
          ??????

base: 12
letters: CFGLMNQRTUWX
difficulty: intermediate