import Control.Monad (replicateM) import Control.Applicative ((<$>), (<*>)) import Data.List (nub, find, findIndex) data Point a = Point a a deriving (Eq) instance Show a => Show (Point a) where show (Point x y) = show x ++ " " ++ show y data Vector a = Vector (Point a) deriving (Eq) movePoint :: Integral a => Point a -> Vector a -> Point a movePoint (Point x1 y1) (Vector (Point x2 y2)) = Point (x1 + x2) (y1 + y2) makeVectorP2P :: Integral a => Point a -> Point a -> Vector a makeVectorP2P (Point x1 y1) (Point x2 y2) = Vector (Point (x2 - x1) (y2 - y1)) vSize :: (Integral a, Floating b) => Vector a -> b vSize (Vector (Point x y)) = sqrt $ fromIntegral (x ^ 2 + y ^ 2) vPlus :: Integral a => Vector a -> Vector a -> Vector a vPlus (Vector (Point x1 y1)) (Vector (Point x2 y2)) = Vector (Point (x1 + x2) (y1 + y2)) dotProd :: Integral a => Vector a -> Vector a -> a dotProd (Vector (Point x1 y1)) (Vector (Point x2 y2)) = x1 * x2 + y1 * y2 isVertical :: Integral a => Vector a -> Vector a -> Bool isVertical a b = dotProd a b == 0 genPerm :: Eq a => Int -> [a] -> [[a]] genPerm n l = filter (\x -> nub x == x) $ replicateM n l splitAt' :: Int -> [a] -> [[a]] splitAt' n xs | length xs <= n = [xs] | otherwise = [fst xs'] ++ (splitAt' n $ snd xs') where xs' = splitAt n xs solve :: Integral a => Point a -> Point a -> Point a -> Maybe (Point a) solve p1 p2 p3 = ans where f1 [p1, p2] = makeVectorP2P p1 p2 f2 [v1, v2] = isVertical v1 v2 && vSize v1 == vSize v2 vectors = splitAt' 2 $ map f1 $ genPerm 2 [p1, p2, p3] origin = (!!) <$> pure [p1, p2, p3] <*> findIndex f2 vectors point = (\(Vector p) -> p) <$> ((vPlus <$> head <*> last) <$> find f2 vectors) ans = movePoint <$> point <*> (Vector <$> origin) main = do [x1, y1, x2, y2, x3, y3] <- map read . words <$> getLine case solve (Point x1 y1) (Point x2 y2) (Point x3 y3) of Just p -> print p Nothing -> print (-1)