function main (s) {
    s=s.split(" ");
	for(var i=0;i<3;i++)s[i]=parseInt(s[i]);
	if(s[2]-s[1]<=0)console.log("delicious\n");
	else if(s[2]-s[1]<=s[0])console.log("safe\n");
	else console.log("dangerous\n");
}
 
main(require('fs').readFileSync('/dev/stdin', 'utf8'));