????????
      +---------
HWEWF | JRGHUGGJ
       -JPEPN
        =====
         NGFWG
        -HWEWF
         =====
         PFFEWG
        -WQFEGM
         ======
          GJJUPJ
         -GLJWPU
          ======
          ??????

base: 13
letters: EFGHJLMNPQRUW
difficulty: hard