???????
     ---------
XYYV ) NMUJZMX
      -WTMV
       ====
       XGLVZ
      - QHQJ
       =====
         ZWNM
        -HPMG
         ====
          MMMX
         -MWNJ
          ====
          ????

base: 16
symbols: GHJLMNPQRTUVWXYZ
difficulty: medium
missing: R