[error] DEADLOCK/NODUP: no remaining values
            0C6
      +--------
9C597 | 461A7C1
       -3C245
        =====
         A333C
        -AB079
         =====
          3BC41
         -0B90A
          =====
          9B460

base: 13
letters: 0123456789ABC
difficulty: medium
missing: 8