?????????
      +----------
PWPRV | JUZYTGXRR
       -QUJNG
        =====
         LYYUG
        -LQNXH
         =====
          GMJRX
         -ULGZH
          =====
           YHMVR
          -MPYHY
           =====
           PNLZGR
          -PNTHNX
           ======
           ??????

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: medium