import Control.Applicative ((<$>))

getRemainder :: [Int] -> [Int]
getRemainder cs@(b0 : _)
    | b0 == 0            = [0]
    | b1 == 0 && b2 == 0 = [b0]
    | b1 == 0 && b2 /= 0 = [b0, 0, b2]
    | b2 == 0            = [b0, b1]
    | otherwise          = [b0, b1, b2]
    where
        fp1 = sum cs
        fm1 = sum $ zipWith (*) cs $ cycle [1, -1]
        b2 = subtract b0 $ flip div 2 $ fp1 + fm1
        b1 = flip div 2 $ fp1 - fm1

main :: IO ()
main = do
    _ <- getLine
    bs <- getRemainder . map read . words <$> getLine
    print $ subtract 1 $ length bs
    putStrLn $ unwords $ map show bs