fun main(args: Array<String>) {
    val input = readLine()!!.split(" ").map{x -> x.toInt()}
    val X = input[0]
    val A = input[1]
    val B = input[2]

    fun taste(x: Int) : String {
        if (x >= 0) return "delicious"
        else if (x+X >= 0) return "safe"
        else return "dangerous"
    }

    println(taste(A-B))
}