function Main(input) {
    input = input.split("\n");
    var line = input[0].split(" ");
    var date = parseInt(line[0]);
    var length = parseInt(line[1]);
    var days = parseInt(line[2]);
    
    if(days>date+length){
        console.log("dangerous");
    } else if(days<=date+length && days>date){
        console.log("safe");
    } else {
        console.log("delicious");
    }
 
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));