#include <stdio.h>
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <string>
#include <iostream>
#include <stdio.h>
#include <queue>
#include <cmath>
#include <utility>
#include <map>
#include <functional>

using namespace std;
typedef long long ll;
typedef vector<int> vecint;
#define rep(i,a,b) for(int i=(a);i<(b);++i)
#define MAX(a,b) (a>b?a:b)
#define MIN(a,b) (a<b?a:b)

#define MAX_V 200
#define INF 1e+9





int main() {
	int A, B;
	int X;
	cin >> X >> A >> B;
	if (A >= B)
		cout << "delicious";
	else if (X >= B - A)
		cout << "safe";
	else
		cout << "dangerous";

	return 0;
}

