A525
      +---------
38B9C | 5ABB05C0
       -38B9C
        =====
        081665
       -00A35B
        ======
         7B754C
        -7866C7
         ======
          087780
         -00A35B
          ======
           91CC3

base: 13
letters: 0123456789ABC
difficulty: medium
missing: 2