Problem:
Score : 100 points

Problem Statement

Takahashi has a strong stomach. He never gets a stomachache from eating something whose "best-by" date is at most X days earlier.
He gets a stomachache if the "best-by" date of the food is X+1 or more days earlier, though.

Other than that, he finds the food delicious if he eats it not later than the "best-by" date. Otherwise, he does not find it delicious.

Takahashi bought some food A days before the "best-by" date, and ate it B days after he bought it.

Write a program that outputs delicious if he found it delicious, safe if he did not found it delicious but did not get a stomachache either, and dangerous if he got a stomachache.

Constraints

1 ≤ X,A,B ≤ 10^9

Input

Input is given from Standard Input in the following format:

X A B

Output

Print delicious if Takahashi found the food delicious; print safe if he neither found it delicious nor got a stomachache; print dangerous if he got a stomachache.

Sample Input 1

4 3 6

Sample Output 1

safe

He ate the food three days after the "best-by" date. It was not delicious or harmful for him.

Sample Input 2

6 5 1

Sample Output 2

delicious

He ate the food by the "best-by" date. It was delicious for him.

Sample Input 3

3 7 12

Sample Output 3

dangerous

He ate the food five days after the "best-by" date. It was harmful for him.

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
#include <boost/multiprecision/cpp_int.hpp>

#define repd(i, a, b) for (ll i = (a); i < (b); i++)
#define rep(i, n) repd(i, 0, n)

using namespace std;

namespace mp = boost::multiprecision;
using Bint = mp::cpp_int;

using ll = long long;
ll mod = pow(10, 9) + 7;

template <typename T> void output(T, ll);
ll gcd(ll, ll);
ll lcm(ll, ll);
Bint comb(Bint, Bint);
void prime_map(map<ll, ll> &, ll);

int main() {
    // source
    int x, a, b;
    cin >> x >> a >> b;
    if (b - a <= 0) {
        cout << "delicious" << endl;
    } else {
        if (b - a <= x) {
            cout << "safe" << endl;
        } else {
            cout << "dangerous" << endl;
        }
    }
    return 0;
}

Bint comb(Bint a, Bint b) {
    Bint ans = 1;

    if (a < b) {
        return 0;
    }

    rep(i, b) {
        ans *= a - i;
        ans /= i + 1;
    }

    return ans;
}

template <typename T> void output(T a, int precision) {
    if (precision > 0) {
        cout << setprecision(precision) << a << "\n";
    } else {
        cout << a << "\n";
    }
}

template <typename T> T min(T a, T b) {

    if (a < b) {
        return a;
    } else {
        return b;
    }
}

ll gcd(ll a, ll b) {
    if (b == 0) {
        return a;
    }
    return gcd(b, a % b);
}

ll lcm(ll a, ll b) { return a * b / gcd(a, b); }

void prime_map(map<ll, ll> &m, ll num) {
    ll cache = num;
    repd(i, 2, sqrt(num) + 2) {
        if (num % i == 0) {
            if (m[i] == 0) {
                m[i] = 1;
            } else {
                m[i]++;
            }

            num /= i;
            break;
        }
    }

    if (cache == num) {
        if (m[num] == 0) {
            m[num] = 1;
        } else {
            m[num]++;
        }
        return;
    } else {
        prime_map(m, num);
    }
}