YFMN
      +---------
YXGXF | NYRCYYFM
       -NFMFF
        =====
         RXCYYF
        -RNHFXF
         ======
          RYRHFM
         -RFMNXF
          ======
           RXYXM

base: 12
letters: CEFGHMNPRWXY
hints: P << E, C << W
difficulty: hard
missing: W P E