F0DE
      +---------
ECF46 | 58ADE28C
       -8FB5D
        =====
        E9DA82
       -EF7839
        ======
         F3CD38
        -F50F71
         ======
           3552C
          -5311F
           =====
            2F88

base: 16
letters: 0123456789ABCDEF
difficulty: hard