RFFR
      +---------
PTXRX | FGRGRTQP
       -YLUUP
        =====
        PTPFTT
       -PGYGRL
        ======
         PURLQQ
        -PGYGRL
         ======
           LRNLP
          -YLUUP
           =====
            QQTN

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