6450
      +---------
25459 | 35BB2873
       -93B3C
        =====
        687CB8
       -651112
        ======
         B7CB67
        -B0B36B
         ======
          CBC133
         -C13B34
          ======
            2712

base: 13
letters: 0123456789ABC
difficulty: easy
restrictions: no multiplication
missing: A