????????
      +---------
GLWHW | HEXGYNRG
       -GLWHW
        =====
        NMNLGN
       -NNXYMT
        ======
         EELLMR
        -NYHEWY
         ======
          GEMLNG
         -GRFEUL
          ======
          ??????

base: 13
letters: EFGHLMNRTUWXY
difficulty: medium