ZRZG
      +---------
RRTJZ | VXMVRMGM
       -WWXZR
        =====
        JJGMNM
       -JJJRRW
        ======
          YZUHG
         -WWXZR
          =====
          LXJGVM
         -LMWJPX
          ======
           ZVUXG

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: hard
missing: Q