900
      +---------
89155 | BC8A30C7
       -B08871
        ======
          1B5CC
         -89155
          =====
           85277
          -89155
           =====
             2AB

base: 13
letters: 0123456789ABC
hints: 2 << 6, 3 + 3 = 6
difficulty: medium
restrictions: no multiplication
missing: 6 4