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

    (x, a, b) match {
      case _ if a <= b => println("delicious")
      case _ if b <= x + a => println("safe")
      case _ => println("dangerous")
    }
  }
}
