[error] DEADLOCK/NODUP: no remaining values
        ????????
      +---------
63273 | 34618999
       -30118
        =====
         15779
        -63273
         =====
         619769
        -668681
         ======
          614909
         -668681
          ======
          ??????

base: 10
letters: 0123456789
hints: 2 << 9
difficulty: hard