function main(input) {
  input = input.trim();
  const [x,a,b] = input.split(" ").map(Number);
 
  if(b-a<=0){
     console.log("delicious");
  }else if(b-a<=x){
     console.log("safe");
  }else{          
     console.log("dangerous");
  }
}
main(require("fs").readFileSync("/dev/stdin", "utf8"));