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

      if ( b <= a ) println("delicious")
      else if ( b <= a + d ) println("safe")
      else if ( b > a + d) println("dangerous")
  }
}