8B4D
      +---------
08358 | CE6FCEDC
       -08358
        =====
        43735E
       -4A540B
        ======
         D623BD
        -D07D54
         ======
          80ACCC
         -8AD90D
          ======
           92741

base: 16
letters: 0123456789ABCDEF
difficulty: challenging
missing: 1