module Main where

main = ant 0 []

ant i as
    | 5 == i = readLn >>= doChk as
    | otherwise = readLn >>= (ant (i+1)) . (:as)

doChk as k =
    case (chk as k) of
        True -> putStrLn "Yay!"
        False -> putStrLn ":("

chk :: [Int] -> Int -> Bool
chk as k = all (les k) $ [(x,y)|x<-as,y<-as,x < y]

les k (a,b) = (b - a) <= k