????????
      +---------
ZHPNY | ZMXVPPZR
       -ZHPNY
        =====
         YMZUP
        -HLUZN
         =====
          LHGXZ
         -MMHPH
          =====
           GNTUR
          -JRMRQ
           =====
           ???H?

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: hard
hints: P << R
missing: W