output_description: Print the minimum number of operations required to make A, B and C all equal.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      A B C
attempt: def c_same_integers(A, B, C):
      # A,B,Cの和と、これらのうち最大のもの(Mとする)との偶奇が一致するなら、
      # 最終的に3つの整数はMとなる
      # 偶奇が一致しないなら、最終的に3つの整数はM+1となる
      m = max(A, B, C)
      parity = 3 * max(A, B, C) % 2 == (A + B + C) % 2
      max_value = m if parity else m + 1
      # 3数の和は1回の操作で2増えるため,ans回の操作が必要
      ans = (3 * max_value - (A + B + C)) // 2
      return ans
  
  
  A, B, C = [int(i) for i in input().split()]
  print(c_same_integers(A, B, C))
  
problem_description: Statement
  
  You are given three integers A, B and C. Find the minimum number of operations
  required to make A, B and C all equal by repeatedly performing the following
  two kinds of operations in any order:
  
    * Choose two among A, B and C, then increase both by 1.
    * Choose one among A, B and C, then increase it by 2.
  
  It can be proved that we can always make A, B and C all equal by repeatedly
  performing these operations.
samples: [{"input": "2 5 4", "output": "2\n    \n\nWe can make A, B and C all equal by the following operations:\n\n  * Increase A and C by 1. Now, A, B, C are 3, 5, 5, respectively.\n  * Increase A by 2. Now, A, B, C are 5, 5, 5, respectively.\n\n* * *"}, {"input": "2 6 3", "output": "5\n    \n\n* * *"}, {"input": "31 41 5", "output": "23"}]