function main(input) {
  input = input.trim();
  const [x,a,b] = input.split(" ").map(Number);

  if(x+1<b-a){
    console.log("dangerous");
  }else if(x<b-a){
     console.log("safe");
  }else{          
     console.log("delicious");
  }           
}
main(require("fs").readFileSync("/dev/stdin", "utf8"));