import Control.Applicative
import Data.List
import Data.Char

getInt :: IO Integer
getInt = (\a -> read a :: Integer) <$> getLine

getIntArray :: IO [Integer]
getIntArray = ((map (\a -> read a :: Integer)) . words) <$> getLine

getStrArray :: Integer -> IO [String]
getStrArray 0 = return [] :: IO [String]
getStrArray n = (:) <$> getLine <*> (getStrArray (n - 1))

canEat :: [Integer] -> String
canEat [x, a, b]
    | b - a < 0 = "delicious"
    | b - a < x = "safe"
    | otherwise = "dangerous"

main = do
    putStrLn =<< (canEat <$> getIntArray)
