function Main(input) {
  const numbers = input.split(' ').map(n => Number(n));
  const x = numbers[0];
  const a = numbers[1];
  const b = numbers[2];

  if(a > b) {
    console.log('delicious');
  } else if(b - a < x + 1) {
    console.log('safe');
  } else {
    console.log('dangerous');
  }
}

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