507C
      +---------
54223 | BF5A35B9
       -54223
        =====
         C3065
        -7EBB0
         =====
          4588B
         -D1FF7
          =====
           AD3A9
          -A6449
           =====
            3E56

base: 16
letters: 0123456789ABCDEF
difficulty: medium