HNJ
      +---------
JNNHN | HNHUPMNW
       - JNNHN
        ======
         NUFUQN
        -LXNWUW
         ======
          PXWJFW
         -PNJUWQ
          ======
           FLFPX

base: 11
letters: FHJLMNPQUWX
difficulty: intermediate
restrictions: no multiplication