import Data.Maybe
import Data.List
import Control.Applicative

main = do
    n <- read <$> getLine
    c <- read <$> getLine
    v <- read <$> getLine
    s <- map read . words <$> getLine
    t <- map read . words <$> getLine
    y <- map read . words <$> getLine
    m <- map read . words <$> getLine
    print $ no1 n c v s t y m

no1 :: Int -> Int -> Int -> [Int] -> [Int] -> [Int] -> [Int] -> Int
no1 n c v s t y m = fromMaybe (-1) $ no1' n c v s t y m

no1' :: Int -> Int -> Int -> [Int] -> [Int] -> [Int] -> [Int] -> Maybe Int
no1' n c _ s t y m = maybeMinimum $ map time $ filter (\a -> place a == n) $  foldl' (>>=) [PlaceCost { place = 1, coin = c, time = 0 }] $ replicate n (`fromTo` createRouteList s t y m)

data PlaceCost = PlaceCost { place :: Int, coin :: Int, time :: Int}
    deriving (Show)

data Route = Route { from :: Int, to :: Int, cost :: Int, rtime :: Int}
    deriving (Show)

fromTo :: PlaceCost -> [Route] -> [PlaceCost]
fromTo pc [] = [pc]
fromTo pc (r:rs)
    | place pc /= from r = fromTo pc rs
    | remainCoin < 0 = fromTo pc rs
    | otherwise = PlaceCost { place = to r, coin = remainCoin, time = tookTime } : fromTo pc rs
    where remainCoin = coin pc - cost r
          tookTime = time pc + rtime r

createRouteList :: [Int] -> [Int] -> [Int] -> [Int] -> [Route]
createRouteList = zipWith4 (\s t y m -> Route { from = s , to = t, cost = y, rtime = m })

maybeMinimum :: (Ord a) => [a] -> Maybe a
maybeMinimum [] = Nothing
maybeMinimum x = Just $ minimum x