object Main extends App {
    val in = readLine.split(" ").map(_.toInt)
    val x = in(0)
    val a = in(1)
    val b = in(2)

    val ret = if (b - a <= 0) {
      "delicious"
    } else if (b - a <= x){
      "safe"
    } else {
      "dangerous"
    }
    println(ret)

}
