output_description: Among A, B and C, print the integer that is different from the rest.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      A B C
attempt: #!/usr/bin/env python3
  from collections import defaultdict
  from collections import deque
  from heapq import heappush, heappop
  import sys
  import math
  import bisect
  import random
  import itertools
  
  sys.setrecursionlimit(10**5)
  stdin = sys.stdin
  bisect_left = bisect.bisect_left
  bisect_right = bisect.bisect_right
  
  
  def LI():
      return list(map(int, stdin.readline().split()))
  
  
  def LF():
      return list(map(float, stdin.readline().split()))
  
  
  def LI_():
      return list(map(lambda x: int(x) - 1, stdin.readline().split()))
  
  
  def II():
      return int(stdin.readline())
  
  
  def IF():
      return float(stdin.readline())
  
  
  def LS():
      return list(map(list, stdin.readline().split()))
  
  
  def S():
      return list(stdin.readline().rstrip())
  
  
  def IR(n):
      return [II() for _ in range(n)]
  
  
  def LIR(n):
      return [LI() for _ in range(n)]
  
  
  def FR(n):
      return [IF() for _ in range(n)]
  
  
  def LFR(n):
      return [LI() for _ in range(n)]
  
  
  def LIR_(n):
      return [LI_() for _ in range(n)]
  
  
  def SR(n):
      return [S() for _ in range(n)]
  
  
  def LSR(n):
      return [LS() for _ in range(n)]
  
  
  mod = 1000000007
  inf = float("INF")
  
  
  # A
  def A():
      a, b, c = LI()
      if a == b:
          print(c)
      if b == c:
          print(a)
      if a == c:
          print(b)
      return
  
  
  # B
  def B():
      return
  
  
  # C
  def C():
      return
  
  
  # D
  def D():
      return
  
  
  # E
  def E():
      return
  
  
  # F
  def F():
      return
  
  
  # G
  def G():
      return
  
  
  # H
  def H():
      return
  
  
  # Solve
  if __name__ == "__main__":
      A()
  
problem_description: Statement
  
  You are given three integers, A, B and C.  
  Among them, two are the same, but the remaining one is different from the
  rest.  
  For example, when A=5,B=7,C=5, A and C are the same, but B is different.  
  Find the one that is different from the rest among the given three integers.
samples: [{"input": "5 7 5", "output": "7\n    \n\nThis is the same case as the one in the statement.\n\n* * *"}, {"input": "1 1 7", "output": "7\n    \n\nIn this case, C is the one we seek.\n\n* * *"}, {"input": "-100 100 100", "output": "-100"}]