#include <bits/stdc++.h>

using namespace std;

#define FOR(i, j, k) for(int i = j; i < k; ++i)
#define rep(i, j) FOR(i, 0, j)
#define FORr(i, j, k) for(int i = j; i >= k; --i)
#define repr(i, j) FOR(i, j, 0)
#define INF (1 << 30)

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> P;
typedef pair<P, int> Pi;

const int MOD = 1e9 + 7;
const int dy[]={0, 0, 1, -1};
const int dx[]={1, -1, 0, 0};

template <class T> void chmin(T& a, const T& b) { a = min(a, b); }
template <class T> void chmax(T& a, const T& b) { a = max(a, b); }

int main() {
	int X, A, B;
	scanf("%d %d %d", &X, &A, &B);
	int tmp = A - B;
	if(tmp < 0) {
		if(abs(tmp) <= X) printf("safe\n");
		else printf("dangerous\n");
	}
	else printf("delicious\n");
	return 0;
}