HJX
      +--------
RXXYL | LWWFJJM
       -RXXYL
        =====
        HNNFXJ
       -HWTTQN
        ======
         UGNMNM
        -UGTUXW
         ======
           GRYR

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