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: H, W = map(int, input().split())
  value = H * W
  # 3つの長方形を(hi,wi)として考える
  
  # h1 == H 横に3分割パターンか縦長一つ横二つパターン
  # h1 + h2 = H 縦長1つ横2つパターン
  # h1 + h3 = H 縦長2つ横1つパターン
  ##h1 + h2 + h3 = H 縦に3分割パターン
  
  # 横に3分割パターン
  if W % 3 == 0:
      value = 0
  else:
      value = H
  
  # 縦に3分割
  if H % 3 == 0:
      value = 0
  else:
      value = min(value, W)
  
  # 縦長一つ横二つパターン
  if W % 3 != 0:  # 3で割り切れるならすでに上記で0になってる
      for i in range(3):
          w1 = W // 3 - 1 + i
          s1 = H * w1
          w_amari = W - w1
          for j in range(3):
              h1 = H // 2 - 1 + j
              s2 = h1 * w_amari
              s3 = H * W - s1 - s2
              value2 = max(s1, s2, s3) - min(s1, s2, s3)
              # print(s1,s2,s3)
              value = min(value, value2)
  # 縦長2つ横1つパターン
  if H % 3 != 0:  # 3で割り切れるならすでに上記で0になってる
      for i in range(3):
          h1 = H // 3 - 1 + i
          s1 = h1 * W
          h_amari = H - h1
          for j in range(3):
              w1 = W // 2 - 1 + j
              s2 = h_amari * w1
              s3 = H * W - s1 - s2
              value3 = max(s1, s2, s3) - min(s1, s2, s3)
              value = min(value, value3)
  
  print(value)
  
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"}]