Problem:
Score : 300 points

Problem 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.

Constraints

0 \leq A,B,C \leq 50

All values in input are integers.

Input

Input is given from Standard Input in the following format:

A B C

Output

Print the minimum number of operations required to make A, B and C all equal.

Sample Input 1

2 5 4

Sample Output 1

2

We can make A, B and C all equal by the following operations:

Increase A and C by 1. Now, A, B, C are 3, 5, 5, respectively.

Increase A by 2. Now, A, B, C are 5, 5, 5, respectively.

Sample Input 2

2 6 3

Sample Output 2

5

Sample Input 3

31 41 5

Sample Output 3

23

Solution in Python (3.4.3) (judge verdict: Runtime Error)

numList = input().split()
numList = list(map(int, numList))
commandList = [
	[2,0,0],
	[0,2,0],
	[0,0,2],
	[0,1,1],
	[1,0,1],
	[1,1,0]
]
numListList = [numList]

def search(depth):
	global numListList
	tmpList = []
	for numList in numListList:
		for command in commandList:
			sumedList = sumList(numList, command)
			if check(sumedList, depth+1):
				return
			tmpList.append(sumedList)
	numListList = tmpList
	search(depth+1)

def sumList(list1, list2):
	return [list1[0]+list2[0], list1[1]+list2[1], list1[2]+list2[2]]

def check(list1, count):
	if list1[0] == list1[1] and list1[1] == list1[2]:
		print(count)
		return True

	if list1[0] == list1[1]:
		if list1[0] > list1[2] and (list1[0]-list1[2])%2 == 0:
			print(int(count+(list1[0]-list1[2])/2))
			return True
		if list1[2] > list1[0]:
			print(int(count+(list1[2]-list1[0])))
			return True

	if list1[1] == list1[2]:
		if list1[1] > list1[0] and (list1[1]-list1[0])%2 == 0:
			print(int(count+(list1[0]-list1[2])/2))
			return True
		if list1[0] > list1[1]:
			print(int(count+(list1[0]-ist1[1])))
			return True

	if list1[0] == list1[2]:
		if list1[0] > list1[1] and (list1[0]-list1[1])%2 == 0:
			print(int(count+(list1[0]-list1[1])/2))
			return True
		if list1[1] > list1[0]:
			print(int(count+(list1[1]-list1[0])))
			return True

	

search(0)