PFE
      ----------
QQWEP ) PYXQXHFP
       -XQCCEH
        ======
         FEXCWF
        -YQHWHN
         ======
          EHFYPP
         -CQXYXQ
          ======
           HGWWH

base: 11
symbols: CEFGHNPQWXY
difficulty: intermediate
restrictions: no multiplication