-- import Prelude hiding (abs)
import Control.Monad
import Control.Arrow ((&&&))
import Data.List (nub, sort, group, find)
import Data.Maybe (fromMaybe, fromJust)
import qualified Data.IntMap as M

type Counter = M.IntMap Int

main :: IO ()
main = do
    [h, w] <- (map read . words) <$> getLine
    print $ solve (h,w)

-- |
--
-- >>> solve (3,5)
-- 0
--
-- >>> solve (4,5)
-- 2
--
-- >>> solve (5,5)
-- 4
--
-- >>> solve (100000, 2)
-- 1
--
-- >>> solve (100000, 100000)
-- 50000
solve :: (Int,Int) -> Int
solve (h,w) = minimum $ map (calc (h,w)) $ sequence [[1 .. h], [1 .. w]]


calc :: (Int,Int) -> [Int] -> Int
calc (h,w) [y,x] = maximum ss - minimum ss
  where ss = splitRect3 (h,w) [y,x]

splitRect3 :: (Int,Int) -> [Int] -> [Int]
splitRect3 (h,w) [y,x]
  | h == y && w == x  = [y * x, 0, 0]
  | h == y = y * x : splitRect2 (h, w - x)
  | w == x = y * x : splitRect2 (h - y, w)
  | otherwise = y * x : splitXY (h,w) [x,y]

splitXY :: (Int,Int) -> [Int] -> [Int]
splitXY (h,w) [x,y]
  | dx > dy   = [sy1, sy2]
  | otherwise = [sx1, sx2]
  where
    sy1 = h * (w - x)
    sy2 = (h - y) * x
    dy = abs $ sy1 - sy2
    sx1 = y * (w - x)
    sx2 = (h - y) * w
    dx = abs $ sx1 - sx2

splitRect2 :: (Int,Int) -> [Int]
splitRect2 (h,w)
  | dh > dw   = [h * w1, h * w2]
  | otherwise = [w * h1, w * h2]
  where
    h1 = h `div` 2
    h2 = h - h1
    w1 = w `div` 2
    w2 = w - w1
    dh = abs (h1 - h2) * w
    dw = abs (w1 - w2) * h
