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 PyPy3 (2.4.0) (judge verdict: Accepted)

import math
import queue
import bisect
import heapq
import time
import itertools

mod = int(1e9+7)

def swap(a,b):
    return (b,a)

def gcd(a,b): #最大公約数
    if (a<b):
        a,b = swap(a,b)
    if (b==0):
        return a
    else:
        return gcd(b,a%b)

def lcm(a,b): #最小公倍数
    return a/gcd(a,b)*b

def divisors(a): # 約数列挙
    divisors = []
    for i in range(1,int(a**0.5)+1):
        if a%i==0:
            divisors.append(i)
            if i!=a//i:
                divisors.append(a//i)
    return divisors

def is_prime(a): #素数判定
    if a<2:
        return False
    elif a==2:
        return True
    elif a%2==0:
        return False
    sqrt_num = int(a**0.5)
    for i in range(3,sqrt_num+1,2):
        if a%i==0:
            return False
    return True

def prime_num(a): #素数列挙
    pn = [2]
    for i in range(3,int(a**0.5),2):
        prime = True
        for j in pn:
            if i%j==0:
                prime = False
                break
        if prime:
            pn.append(i)
    return pn

def prime_fact(a): #素因数分解
    sqrt = math.sqrt(a)
    res = []
    i = 2
    if is_prime(a):
        res.append(a)
    else:
        while a!=1:
            while a%i==0:
                res.append(i)
                a //= i
            i += 1
    return res

def main():
    x,a,b = map(int,input().split())
    if a-b>=0:
        print('delicious')
    elif b-a<=x:
        print('safe')
    else:
        print('dangerous')
    return

if __name__=='__main__':
    main()