DC04
      +---------
1D56B | A03368BB
       -1D56B
        =====
        DBEE38
       -D3AE2C
        ======
         D8230B
        -D8D7DA
         ======
           5CE8B
          -C08B4
           =====
           1DA51

base: 15
letters: 0123456789ABCDE
difficulty: medium
missing: 9