PGLT
      +---------
JGPRF | FJURGFFH
       -JGPRF
        =====
        LPGHUF
       -EHLUEP
        ======
         EELGTF
        -PTRRLG
         ======
          RHPGRH
         -RUTMGJ
          ======
           ERRHR

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