import Control.Applicative ((<$>))
import Control.Monad (replicateM)

main :: IO ()
main = solve <$> replicateM 26 readLn >>= print

solve :: [Int] -> Int
solve [_,_,_,d,e,_,_,h,_,_,_,l,_,_,o,_,_,r,_,_,_,_,w,_,_,_] = d * e * h * r * w * (let o2 = o `div` 2 in o2 * (o - o2)) * f l
  where f l = maximum . map (\x -> x * (l-x) * (l-x-1) `div` 2) $ [0..l]