TPH
      +--------
UNYJR | LHTWHXT
       -HGHTQ
        =====
        JWWPLX
       -JJQNGW
        ======
         GWNFGT
        -GTPNJT
         ======
          GUQPM

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