NTU
      +---------
TEMGT | ERGGRNUX
       -EQUNQQ
        ======
         XFQUEU
        -XGRTNN
         ======
          MMFPGX
         -GPNWXW
          ======
           XUJFR

base: 13
letters: EFGJMNPQRTUWX
difficulty: intermediate
restrictions: no multiplication