????????
      +---------
UMTNX | MZXQVGQG
       -QYUZG
        =====
        HMJXXG
       -HMHMNR
        ======
          NUGWQ
         -QYUZG
          =====
           QLRUG
          -UMTNX
           =====
           ?????

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: medium
hints: remainder is UXNVX
missing: P