????????
      +---------
XYZUH | HJYNMHGX
       -NYPXZ
        =====
         ZVXNH
        -XYZUH
         =====
         LVTPRG
        -LGHHNW
         ======
          XRWXXX
         -WTURNH
          ======
          ??????

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: medium
attributes: fun
missing: Q