D9A6
      +---------
6C09E | 431189D3
       -F8BA2
        =====
        C9C689
       -CFC2B2
        ======
         C2C99D
        -54E752
         ======
           A81D3
          -83DBE
           =====
           5CEE4

base: 16
letters: 0123456789ABCDEF
difficulty: hard