7D3E
      +---------
BF729 | C604763F
       -BF729
        =====
        91AA86
       -931A05
        ======
         A15C63
        -A09172
         ======
          BD7BFF
         -B2034D
          ======
           08E0A

base: 16
letters: 0123456789ABCDEF
difficulty: hard
missing: E