[error] DEADLOCK/NODUP: no remaining values
        ????????
      +---------
9EA85 | C9579C0C
       -9EA85
        =====
        20E64C
       -2D6D30
        ======
         922BA0
        -814319
         ======
          9224DC
         -814319
          ======
          ??????

base: 15
letters: 0123456789ABCDE
difficulty: hard