MPF
      +---------
MEGME | TTPEYMFR
       -TGNHQH
        ======
         PNHQWF
        - MEGME
         ======
          UNHNHR
         -UNWFNU
          ======
            GGHG

base: 13
letters: EFGHMNPQRTUWY
difficulty: medium
restrictions: no multiplication