module Main where

  import           Control.Monad
  import           Data.List
  import           Data.Ord
  import           Data.List.Split
  import           Data.Array.IO
  import qualified Data.Vector.Unboxed as V
  
  main :: IO ()
  main = do
    as <- sort <$> replicateM 5 readLn :: IO [Int]
    d <- readLn :: IO Int
    if f as (head as) d then putStrLn "Yay!" else putStrLn ":("
  
  f [a] m d = a - m <= d
  f (a:b:cs) m d = a - m <= d && f (b:cs) m d
  