D85
      +--------
C751E | 0F73FAD
       -94D0D
        =====
        C601CA
       -C59FF8
        ======
         EDD28D
        -EE2655
         ======
          E6F58

base: 16
letters: 0123456789ABCDEF
difficulty: hard
hints: A << 8, C << 6
missing: B