3964
      +---------
D371D | 14664E44
       -D371D
        =====
        37B8BE
       -329C02
        ======
         91A4C4
        -9074A0
         ======
          60EE34
         -62DDE2
          ======
           27696

base: 15
letters: 0123456789ABCDE
difficulty: hard
missing: 5