function main(input) {
   input = input.trim();
  const a = input.split(" ").map(Number);
 console.log(a[1]-a[2]>=0 ?"delicious"
		    :a[2]-a[1]>a[0] ?"dangerous"
		    :"safe");
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));