    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"));