[error] DEADLOCK/NODUP: no remaining values
        ????????
      +---------
12278 | 75417391
       -39589
        =====
        11B153
       - 84B82
        ======
         12B429
        -11B671
         ======
          1BA501
         - 84B82
          ======
          ??????

base: 12
letters: 0123456789AB
difficulty: intermediate