function Main(input) {
	input = input.trim().split(" ").map((a)=>Number(a));
  var X = input[0];
  var A = input[1];
  var B = input[2];
  
  if(A + X < B){
     console.log("dangerous");
     }else if(A - B >= 0){
    console.log("delicious");
  }else{
    console.log("safe");
  }
  
}

Main(require("fs").readFileSync("/dev/stdin", "utf8"));
