import Data.Maybe
import Data.List
import Data.Function
import Control.Applicative
import Debug.Trace

main :: IO ()
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 (\a b -> b a) [PlaceCost { place = 1, coin = c, time = 0 }]
    $ map applyRoute $ sortBy (compare `on` from)
    $ 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)

createRouteList :: [Int] -> [Int] -> [Int] -> [Int] -> [Route]
createRouteList = zipWith4 Route

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

applyRoute :: Route -> [PlaceCost] -> [PlaceCost]
applyRoute _ [] = []
applyRoute r (x:xs)
    | placeComp == GT = applyRoute r xs
    | placeComp == LT = x : applyRoute r xs
    | remainCoin < 0 = x : applyRoute r xs
    | otherwise = minTimeAdd PlaceCost { place = to r, coin = remainCoin
            , time = tookTime } $ x : applyRoute r xs
    where
      remainCoin = coin x - cost r
      tookTime = time x + rtime r
      placeComp = from r `compare` place x

minTimeAdd :: PlaceCost -> [PlaceCost] -> [PlaceCost]
minTimeAdd pc pcs
    | null filterPcs = pc : pcs
    | time pc > time (head filterPcs) = pcs
    | otherwise = pc : dropWhile samePlaceCoin pcs
  where
    filterPcs = filter samePlaceCoin pcs
    samePlaceCoin a = place pc == place a && coin pc == coin a