?????????
      +----------
WNTMY | MNGPWMWGR
       -WNTMY
        =====
        NYNUZM
       -NUUNQL
        ======
          WRYWW
         -WNTMY
          =====
           QGJZG
          -WNTMY
           =====
           GTTXVR
          -GRNLGJ
           ======
           ??????

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: intermediate
missing: H