????????
      +---------
NHMFE | MJHHHNWR
       -MQEHJR
        ======
         FMXFNW
        -FRWWGE
         ======
          MWJQNR
         -FNQNQM
          ======
          ??????

base: 12
letters: EFGHJMNQRUWX
missing: U
difficulty: hard