????????
      +---------
RGPQL | TGRMTQMY
       -UVPQX
        =====
         ZGLMQ
        -GQUMH
         =====
          LVNWM
         -LLMZT
          =====
           WVRXY
          -WGZUG
           =====
           ?????

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: hard
hints: P << Y
missing: J