fun main(args : Array<String>) {
    var (X,A,B)= ReadInts()

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

    

}



fun ReadInts():MutableList<Int>{
    return readLine()!!.split(" ").map{it.toInt()}.toMutableList()
}

fun ReadLongs():MutableList<Long>{
    return readLine()!!.split(" ").map{it.toLong()}.toMutableList()
}
fun ReadDoubles():MutableList<Double>{
    return readLine()!!.split(" ").map{it.toDouble()}.toMutableList()
}
  