function Main(input){
  input = input.split(' ');
  var x = Number(input[0]);
  var a = Number(input[1]);
  var b = Number(input[2]);

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

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