????????
      +---------
38289 | 125D2620
       -38289
        =====
        EEB646
       - 03C1A
        ======
         A34632
        -AA45DE
         ======
          E73160
         - 03C1A
          ======
          ??????

base: 15
letters: 0123456789ABCDE
difficulty: medium