[error] DEADLOCK/NODUP: no remaining values
        ????????
      +---------
04859 | 2306AA67
       -04859
        =====
         793BA
        -04859
         =====
         9011B6
        -990B1A
         ======
          88B967
         - B6501
          ======
          ??????

base: 12
letters: 0123456789AB
difficulty: intermediate
hints: 5 << 6