????????
      +---------
WXTTE | MPFNPHTY
       -XNFTR
        =====
        WFLPRH
       -WHWXNM
        ======
          NFGFT
         -XNFTR
          =====
           TEMHY
          -TGPPX
           =====
           ?????

base: 13
letters: EFGHLMNPRTWXY
difficulty: medium