????????
      +---------
XGRFX | QFQMMWHU
       -HJLPH
        =====
        GLRWGW
       -GHYHMH
        ======
         JPMPQH
        -JGFWNT
         ======
          JUQNHU
         -JNPNUX
          ======
          ??????

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: hard