object MainKt {
  @JvmStatic fun main(args:Array<String>) {
    val (X,A,B)=readLine()!!.split(" ").map(String::toInt)

    println(if(B-A>X) {
      "dangerous"
    } else {
      if(B-A<=0) {
        "delicious"
      } else {
        "safe"
      }
    })
  }
}
