????????
      +---------
30569 | B5498ABA
       -B5A46
        =====
          06AAB
         -07332
          =====
           0038A
          -30569
           =====
          ??????

base: 12
letters: 0123456789AB
missing: 1
difficulty: medium
hints: A << B, 6 << 1, 8 << 9