process.stdin.resume();
process.stdin.setEncoding('utf8');
// Here your code !
process.stdin.on('data', function (chunk) {
    var lines = chunk.toString().split(' ');
    var X = parseInt(lines[0],10);
    var A = parseInt(lines[1],10);
    var B = parseInt(lines[2],10);
    
    var pass_time = B - A;
//    console.log(pass_time);
    if(pass_time <=  0){
        console.log("delicious");
    }else if (pass_time <= X){
        console.log("safe");
    }else{
        console.log("dangerous");
    }

});