55E4
      +---------
9559F | 971976A8
       -9559F
        =====
         F5356
        -9559F
         =====
          04C1A
         -BEEB0
          =====
          E8DF88
         -E205B7
          ======
           1AE0F

base: 16
letters: 0123456789ABCDEF
difficulty: medium