????????
      +---------
HXGHG | RHNXCCGN
       -HXGHG
        =====
         RWFNC
        -HXGHG
         =====
          PHPNG
         -WENFN
          =====
          NFWCRN
         -NENRRH
          ======
          ??????

base: 11
letters: CEFGHNPQRWX
difficulty: hard
missing: Q