[error] DEADLOCK/NODUP: no remaining values
        ????????
      +---------
36615 | 69789700
       -36615
        =====
        849157
       -825389
        ======
         839460
        -825389
         ======
          730540
         -713978
          ======
          ??????

base: 10
letters: 0123456789
difficulty: hard