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# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Linq;
using System.IO;
using System.Collections.Generic;
using System.Text;

namespace AtCoder {
    public class Program {
        static int[] getKeys() {
            var Keys = Console.ReadLine().Split(' ');
            int N = Keys.Length;
            int[] Ns = new int[N];
            for (int i = 0; i < N; i++) {
                Ns[i] = int.Parse(Keys[i]);
            }
            return Ns;
        }
        static int[] getKeys(char delimiter) {
            var Keys = Console.ReadLine().Split(delimiter);
            int N = Keys.Length;
            int[] Ns = new int[N];
            for (int i = 0; i < N; i++) {
                Ns[i] = int.Parse(Keys[i]);
            }
            return Ns;
        }
        static long[] getKeys_L(char delimiter = ' ') {
            var Keys = Console.ReadLine().Split(delimiter);
            int N = Keys.Length;
            long[] Ns = new long[N];
            for (int i = 0; i < N; i++) {
                Ns[i] = long.Parse(Keys[i]);
            }
            return Ns;
        }
        static double[] getKeys_D(char delimiter = ' ') {
            var Keys = Console.ReadLine().Split(delimiter);
            int N = Keys.Length;
            var Ns = new double[N];
            for (int i = 0; i < N; i++) {
                Ns[i] = double.Parse(Keys[i]);
            }
            return Ns;
        }

        public static void Show<T>(T[,] map) {
            int H = map.GetLength(0);
            int W = map.GetLength(1);
            Console.WriteLine("-------------------------");
            for (int i = 0; i < H; i++) {
                for (int j = 0; j < W; j++) {
                    Console.Write(map[i, j] + " ");
                }
                Console.WriteLine();
            }
            Console.WriteLine("-------------------------");
        }
        public static void Show<T>(T[,] map, string delimiter) {
            int H = map.GetLength(0);
            int W = map.GetLength(1);
            Console.WriteLine("-------------------------");
            for (int i = 0; i < H; i++) {
                for (int j = 0; j < W; j++) {
                    Console.Write(map[i, j] + delimiter);
                }
                Console.WriteLine();
            }
            Console.WriteLine("-------------------------");
        }
        public static void Show<T>(IEnumerable<T> ts) {
            foreach (var item in ts) {
                Console.Write(item + " ");
            }
            Console.WriteLine();
        }
        public static void Show<T>(IEnumerable<T> ts, string delimiter) {
            foreach (var item in ts) {
                Console.Write(item + delimiter);
            }
            Console.WriteLine();
        }
        public static void ShowDictionary<T1, T2>(Dictionary<T1, T2> dictionary) {
            foreach (var item in dictionary) {
                Console.WriteLine(item);
            }
        }
        static T[] getUniform<T>(int length, T value) {
            T[] Ts = new T[length];
            for (int i = 0; i < length; i++) {
                Ts[i] = value;
            }
            return Ts;
        }
        static void setUniform<T>(T[] ts, T value) {
            int length = ts.Length;
            for (int i = 0; i < length; i++) {
                ts[i] = value;
            }
        }
        static T[,] getUniform<T>(int row, int col, T value) {
            T[,] Ts = new T[row, col];
            for (int i = 0; i < row; i++) {
                for (int j = 0; j < col; j++) {
                    Ts[j, i] = value;
                }
            }
            return Ts;
        }
        static void setUniform<T>(T[,] ts, T value) {
            int N = ts.GetLength(0);
            int M = ts.GetLength(1);
            for (int i = 0; i < M; i++) {
                for (int j = 0; j < N; j++) {
                    ts[j, i] = value;
                }
            }
        }

        static void Main() {
            var keys = getKeys();
            int date = -keys[1] + keys[2];
            if (date <= 0) {
                Console.WriteLine("delicious");
            } else if (keys[0] >= date) {
                Console.WriteLine("safe");
            } else {
                Console.WriteLine("dangerous");
            }
        }
    }
}