D84
     +-------
EE9D | DA24A0
      -D5C0
       ====
        44CA
       -867E
        ====
         9230
        -91E5
         ====
          29E

base: 15
letters: 0123456789ABCDE
difficulty: hard
hints: C << 8 << 2, D << 0
missing: B