5D36
      +---------
0DE38 | 47E63D04
       -0DE38
        =====
        5423CD
       -5534CA
        ======
         05EAD0
        -B331E0
         ======
          B786A4
         -BCB098
          ======
           04CB3

base: 15
letters: 0123456789ABCDE
difficulty: medium