"use strict";
const Main = (input) => {
	let xs = input.trim().split(' ').map(v=>parseInt(v,10));
  	if(xs[0] + 1 <= (xs[2] -xs[1])){
    console.log('dangerous');
    }else if(xs[0] > (xs[2] -xs[1]) && xs[1] > xs[2]){
    console.log('delicious');
    }else if(xs[0] > (xs[2] -xs[1]) && xs[1] < xs[2]){
    console.log('safe');
    }
}
Main(require('fs').readFileSync('/dev/stdin','utf8'));    