LFCF
      +---------
XUXEM | WRNRJEFW
       -XUXEM
        =====
        LLJFFE
       - RRRWJ
        ======
         LJMNUF
        -LUXCLX
         ======
          LXFCXW
         - RRRWJ
          ======
           XFCJM

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