main :: IO ()
main = do
  input <- (map read . words) <$> getLine
  print $ solve (input!!0) (input!!1) (input!!2)


solve x a b
  | (-a) + b > x = "dangerous"
  | otherwise = safeToEat x a b
  where safeToEat x a b
          | (-a) + b > 0 = "safe"
          | otherwise = "delicious"
