7A65
    +-------
E14 | B924DB
     -0DB
      ===
      27E4
     -1537
      ====
       25ED
      -23C8
       ====
        2EEB
       -27A9
        ====
         79E

base: 15
letters: 0123456789ABCDE
difficulty: medium
hints: 8 << D << 9
missing: 6