
object Main {
  def main(args: Array[String]) {
    val sc = new java.util.Scanner(System.in)
    val x, a, b = sc.nextInt

    val text =
      if (a + x < b) "dangerous"
      else if (a + x > b) "safe"
      else if (a < b) "delicious"

      println(text)
  }
}

