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.
nums = list(map(int, input().split()))
nums.sort()
count = nums[2] - nums[1]
nums[0] += nums[2] - nums[1]
if (nums[2]-nums[0])%2 == 0:
  count += (nums[2]-nums[0])//2
else:
  count += (nums[2]-nums[0])//2 + 2
nums = list(map(int, input().split()))
nums.sort()
count = nums[2] - nums[1]
nums[0] += nums[2] - nums[1]
if (nums[2]-nums[0])%2 == 0:
  count += (nums[2]-nums[0])//2
else:
  count += (nums[2]-nums[0])//2 + 2
print(count)