output_description: Print the minimum possible value of S_{max} - S_{min}.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      H W
attempt: # https://qiita.com/_-_-_-_-_/items/34f933adc7be875e61d0
  # abcde	s=input()	s='abcde'
  # abcde	s=list(input())	s=['a', 'b', 'c', 'd', 'e']
  # 5(1つだけ)	a=int(input())	a=5
  # 1 2	| x,y = map(int,input().split())   |	x=1,y=2
  # 1 2 3 4 5 ... n 　	li = input().split()	li=['1','2','3',...,'n']
  # 1 2 3 4 5 ... n 　	li = list(map(int,input().split()))	li=[1,2,3,4,5,...,n]
  # FFFTFTTFF 　	li = input().split('T')	li=['FFF', 'F', '', 'FF']
  
  # INPUT
  # 3
  # hoge
  # foo
  # bar
  # ANSWER
  # n=int(input())
  # string_list=[input() for i in range(n)]
  
  from collections import defaultdict, Counter
  from math import pi, sqrt
  from bisect import bisect_left, bisect_right
  
  
  def req_S(h, w):
      tmp_s = []
      a_w = w
      for a_h in range(1, h):
          # b, cが横のパターン
          b_h = (h - a_h) // 2
          c_h = h - b_h
          b_w, c_w = w, w
          S = [a_w * a_h, b_w * b_h, c_w * c_h]
          tmp_s.append(max(S) - min(S))
          # b, cが縦のパターン
          b_w = w // 2
          c_w = w - b_w
          b_h, c_h = h - a_h, h - a_h
          S = [a_w * a_h, b_w * b_h, c_w * c_h]
          tmp_s.append(max(S) - min(S))
      return tmp_s
  
  
  #### START
  h, w = map(int, input().split())
  
  all_S = req_S(h, w) + req_S(w, h)
  print(min(all_S))
  
problem_description: Statement
  
  There is a bar of chocolate with a height of H blocks and a width of W blocks.
  Snuke is dividing this bar into exactly three pieces. He can only cut the bar
  along borders of blocks, and the shape of each piece must be a rectangle.
  
  Snuke is trying to divide the bar as evenly as possible. More specifically, he
  is trying to minimize S_{max} \- S_{min}, where S_{max} is the area (the
  number of blocks contained) of the largest piece, and S_{min} is the area of
  the smallest piece. Find the minimum possible value of S_{max} - S_{min}.
samples: [{"input": "3 5", "output": "0\n    \n\nIn the division below, S_{max} - S_{min} = 5 - 5 = 0.\n\n![2a9b2ef47b750c0b7ba3e865d4fb4203.png](https://atcoder.jp/img/arc074/2a9b2ef47b750c0b7ba3e865d4fb4203.png)\n\n* * *"}, {"input": "4 5", "output": "2\n    \n\nIn the division below, S_{max} - S_{min} = 8 - 6 = 2.\n\n![a42aae7aaaadc4640ac5cdf88684d913.png](https://atcoder.jp/img/arc074/a42aae7aaaadc4640ac5cdf88684d913.png)\n\n* * *"}, {"input": "5 5", "output": "4\n    \n\nIn the division below, S_{max} - S_{min} = 10 - 6 = 4.\n\n![eb0ad0cb3185b7ae418e21c472ff7f26.png](https://atcoder.jp/img/arc074/eb0ad0cb3185b7ae418e21c472ff7f26.png)\n\n* * *"}, {"input": "100000 2", "output": "1\n    \n\n* * *"}, {"input": "100000 100000", "output": "50000"}]