function main(input){
  
  var args = input.split(' ');
  var x = ParseInt(args[0],10);
  var a = ParseInt(args[1],10);
  var b = ParseInt(args[2],10);
  var judge = b-a;
  if(judge<=0){
  console.log("delicious");
    break;
  }
  
  if(judge < x+1){
  console.log("safe");
  }
  else{
	console.log("dangerous");
  }
}
main(require('fs').readFileSync('dev/stdin','utf-8'));