XRVH
      +---------
HWXJG | NVHHMMNG
       -HWXJG
        =====
        UNXNWM
       -UUWUYV
        ======
         URULXN
        -UQNGVL
         ======
           MXTMG
          -RNNZU
           =====
           UZYUT

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