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: import sys
  
  h, w = [int(i) for i in input().split()]
  h3 = int(h / 3)
  w3 = int(w / 3)
  ret = sys.maxsize
  # ||| Split
  if h % 3 == 0 or w % 3 == 0:
      ret = 0
  a1 = h3 * w
  a2 = (h3 + 1) * w
  if ret > a2 - a1:
      ret = a2 - a1
  a1 = w3 * h
  a2 = (w3 + 1) * h
  if ret > a2 - a1:
      ret = a2 - a1
  # print("|||:", a2 - a1)
  
  # T Split
  a1 = h3 * w
  a2 = (h - h3) * int(w / 2)
  if w % 2 == 1:
      a2 += h - h3
  a3 = (h - h3) * int(w / 2)
  amin = a1
  if a1 > a3:
      amin = a3
  amax = a2
  if a1 > a2:
      amax = a1
  if ret > (amax - amin):
      ret = amax - amin
  
  # print("T1: ", amax - amin)
  
  h31 = h3 + 1
  a1 = (h31) * w  # 10
  a2 = (h - h31) * int(w / 2)  # 6
  if w % 2 == 1:
      a2 += h - h31  # 9
  a3 = (h - h31) * int(w / 2)
  amin = a1
  if a1 > a3:
      amin = a3
  amax = a2
  if a1 > a2:
      amax = a1
  if ret > (amax - amin):
      ret = amax - amin
  
  # print("T2: ", amax - amin, amax, amin)
  
  h, w = w, h
  h3 = int(h / 3)
  w3 = int(w / 3)
  a1 = h3 * w
  a2 = (h - h3) * int(w / 2)
  if w % 2 == 1:
      a2 += h - h3
  a3 = (h - h3) * int(w / 2)
  amin = a1
  if a1 > a3:
      amin = a3
  amax = a2
  if a1 > a2:
      amax = a1
  if ret > (amax - amin):
      ret = amax - amin
  
  # print("T3: ", amax - amin)
  
  h31 = h3 + 1
  a1 = (h31) * w
  a2 = (h - h31) * int(w / 2)
  if w % 2 == 1:
      a2 += h - h31
  a3 = (h - h31) * int(w / 2)
  amin = a1
  if a1 > a3:
      amin = a3
  amax = a2
  if a1 > a2:
      amax = a1
  if ret > (amax - amin):
      ret = amax - amin
  
  # print("T4: ", amax - amin)
  
  print(int(ret))
  
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"}]