function main(input) {
  input=input.trim();
  const x = parseInt(input.split(" ")[0], 10);
  const a = parseInt(input.split(" ")[1], 10);
  const b = parseInt(input.split(" ")[2], 10);
  if(b<=a){
    console.log("delicious");
  }else if(b-a<=x){
    console.log("safe");
  }else{
    console.log("dangerous");
  }

  

}


main(require('fs').readFileSync('/dev/stdin', 'utf8'));
