function main (str) {
	str = str.split(" ");
	var x= str[0];
	var a= str[1];
	var b= str[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"));