[error] DEADLOCK/NODUP: no remaining values
            525
      +--------
5CE13 | 13E9C0B
       -5CE13
        =====
         46A90
        -C8ABC
         =====
          1D71B
         -5CE13
          =====
          53D6C

base: 15
letters: 0123456789ABCDE
difficulty: hard
missing: 2