function Main(input) {
  input = input.trim()
  input = input.split(" ").map(Number);
if(input[0]>=input[2]){

console.log("delicious")
}else if(input[0]+input[1]>=input[2]){
console.log("safe")
}else{
console.log("dangerous")
}
}Main(require("fs").readFileSync("/dev/stdin", "utf8"));