FLFF
      +---------
ETRRE | TRLEFHFG
       -FNRRF
        =====
        EFLERH
       -EFYRRL
        ======
          WRLNF
         -FNRRF
          =====
           FLNRG
          -FNRRF
           =====
            ENRW

base: 10
letters: EFGHLNRTWY
difficulty: intermediate
restrictions: no multiplication