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, os, math, bisect, itertools, collections, heapq, queue
  
  # from scipy.sparse.csgraph import csgraph_from_dense, floyd_warshall
  from decimal import Decimal
  from collections import defaultdict, deque
  
  sys.setrecursionlimit(10000000)
  
  ii = lambda: int(sys.stdin.buffer.readline().rstrip())
  il = lambda: list(map(int, sys.stdin.buffer.readline().split()))
  fl = lambda: list(map(float, sys.stdin.buffer.readline().split()))
  iln = lambda n: [int(sys.stdin.buffer.readline().rstrip()) for _ in range(n)]
  
  iss = lambda: sys.stdin.buffer.readline().decode().rstrip()
  sl = lambda: list(map(str, sys.stdin.buffer.readline().decode().split()))
  isn = lambda n: [sys.stdin.buffer.readline().decode().rstrip() for _ in range(n)]
  
  lcm = lambda x, y: (x * y) // math.gcd(x, y)
  
  MOD = 10**9 + 7
  MAX = float("inf")
  
  
  def main():
      if os.getenv("LOCAL"):
          sys.stdin = open("input.txt", "r")
  
      H, W = il()
      if W % 3 == 0:
          print(0)
      elif H % 3 == 0:
          print(0)
      else:
          ret = MAX
          for h in range(1, H):
              # 横, 横, 横 分割パターン
              hh = (H - h) // 2
              hmin = min(hh * W, (H - h - hh) * W, h * W)
              hmax = max(hh * W, (H - h - hh) * W, h * W)
  
              # 横, 縦, 縦 分割パターン
              ww = W // 2
              wmin = min((H - h) * (W - ww), (H - h) * ww, h * W)
              wmax = max((H - h) * (W - ww), (H - h) * ww, h * W)
  
              ret = min(ret, abs(hmax - hmin), abs(wmax - wmin))
  
          for w in range(1, W):
              # 縦, 縦, 縦 分割パターン
              ww = (W - w) // 2
              wmin = min(w * H, (W - w - ww) * H, ww * H)
              wmax = max(w * H, (W - w - ww) * H, ww * H)
  
              # 縦, 横, 横 分割パターン
              hh = H // 2
              hmin = min(w * H, hh * (W - w), (H - hh) * (W - w))
              hmax = max(w * H, hh * (W - w), (H - hh) * (W - w))
  
              ret = min(ret, abs(hmax - hmin), abs(wmax - wmin))
  
          print(ret)
  
  
  if __name__ == "__main__":
      main()
  
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"}]