[error] DEADLOCK/NODUP: no remaining values
            BA6B
      +---------
BBAA5 | AC30C804
       -CC658
        =====
         97C78
        -69100
         =====
         180A30
        -175B33
         ======
           AB964
          -CC658
           =====
            515C

base: 13
letters: 0123456789ABC
difficulty: hard
restrictions: no multiplication
missing: 2