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] _ _ = True
f (a:b:cs) m d = not ( a - m > d) && f (b:cs) m d
