????????
      +---------
VXUGH | XMHWYZQN
       -WNRXV
        =====
         NQTNZ
        -HMVGW
         =====
         VRYLTQ
        -VLYHZP
         ======
           TQNHN
          -PRZTM
           =====
           ?????

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: medium
missing: J