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: # https://atcoder.jp/contests/abc093/tasks/arc094_a
  a, b, c = map(int, input().split())
  
  nums = [a, b, c]
  nums.sort()
  
  ans = 0
  if (nums[1] - nums[0]) % 2 == 1:
      # 小さい2つの差が奇数の場合、偶数になるように
      # 小さい2つの数字両方にならないように、1を足す。
      # ここでは、二番目に大きいのと、最大の数に1を足す。
      nums[1] += 1
      nums[2] += 1
      ans += 1
  ans += (nums[1] - nums[0]) // 2　# 一番小さい数が、二番目に大きい数に追いつくようにする。それには2ずつ足すのが良い。
  ans += (nums[2] - nums[1]) # 一番目も二番目も同じかずになったので、両方に１つづ足していき、最大の数と同じになる様にする。
  print(ans)
  
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"}]