[error] DEADLOCK/NODUP: no remaining values
            845
      +--------
013C6 | 5486CA6
       -167B3
        =====
        08589A
       -0BC6A5
        ======
          9A4B6
         -91B7B
          =====
           8918

base: 13
letters: 0123456789ABC
difficulty: hard
missing: 2