WGTX
      +---------
JXQLF | MPWFQLHX
       -JXQLF
        =====
        WJXPHL
       -WRLJYT
        ======
         XJXXHH
        -XGTUPG
         ======
          WMPMLX
         -WMXHYM
          ======
            MXRY

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: hard
missing: N