import Data.List
import Data.Char

main = do
  [a] <- map read . words <$> getLine
  [b] <- map read . words <$> getLine
  [c] <- map read . words <$> getLine
  [d] <- map read . words <$> getLine
  [e] <- map read . words <$> getLine
  [k] <- map read . words <$> getLine
  print $ if (filter (k <) $ map abs [b-a,c-b,d-c,e-d]) == [] then "Yay!" else ":("