import Control.Applicative

main :: IO ()
main = do
    a <- readLn
    b <- readLn
    c <- readLn
    d <- readLn
    e <- readLn
    k <- readLn
    putStrLn $ solve a b c d e k

solve :: Int -> Int -> Int -> Int -> Int -> Int -> String
solve a b c d e k = if b - a > k 
                    || c - a > k
                    || d - a > k
                    || e - a > k
                    || c - b > k 
                    || d - b > k
                    || e - b > k
                    || d - c > k
                    || e - c > k
                    || e - d > k
                    then ":("
                    else "Yay!"
                                 
