import java.util.Scanner

fun main(args: Array<String>){
    val sc = Scanner(System.`in`)
    val x:Int = sc.nextInt()
    val a:Int = sc.nextInt()
    val b:Int = sc.nextInt()

    val ans:String = if(a-b>=0) "delicious"
                     else if(x+a-b>=0) "safe"
                     else "dangerous"

    println(ans)
}
