output_description: 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.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      X A B
attempt: # -*- coding: utf-8 -*-
  
  #############
  # Libraries #
  #############
  
  import sys
  
  input = sys.stdin.readline
  
  import math
  from collections import deque
  from fractions import gcd
  from functools import lru_cache
  
  
  #############
  # Constants #
  #############
  
  MOD = 10**9 + 7
  INF = float("inf")
  
  #############
  # Functions #
  #############
  
  
  ######INPUT######
  def inputI():
      return int(input().strip())
  
  
  def inputS():
      return input().strip()
  
  
  def inputIL():
      return list(map(int, input().split()))
  
  
  def inputSL():
      return list(map(str, input().split()))
  
  
  def inputILs(n):
      return list(int(input()) for _ in range(n))
  
  
  def inputSLs(n):
      return list(input().strip() for _ in range(n))
  
  
  def inputILL(n):
      return [list(map(int, input().split())) for _ in range(n)]
  
  
  def inputSLL(n):
      return [list(map(str, input().split())) for _ in range(n)]
  
  
  #####Inverse#####
  def inv(n):
      return pow(n, MOD - 2, MOD)
  
  
  ######Combination######
  kaijo_memo = []
  
  
  def kaijo(n):
      if len(kaijo_memo) > n:
          return kaijo_memo[n]
      if len(kaijo_memo) == 0:
          kaijo_memo.append(1)
      while len(kaijo_memo) <= n:
          kaijo_memo.append(kaijo_memo[-1] * len(kaijo_memo) % MOD)
      return kaijo_memo[n]
  
  
  gyaku_kaijo_memo = []
  
  
  def gyaku_kaijo(n):
      if len(gyaku_kaijo_memo) > n:
          return gyaku_kaijo_memo[n]
      if len(gyaku_kaijo_memo) == 0:
          gyaku_kaijo_memo.append(1)
      while len(gyaku_kaijo_memo) <= n:
          gyaku_kaijo_memo.append(
              gyaku_kaijo_memo[-1] * pow(len(gyaku_kaijo_memo), MOD - 2, MOD) % MOD
          )
      return gyaku_kaijo_memo[n]
  
  
  def nCr(n, r):
      if n == r:
          return 1
      if n < r or r < 0:
          return 0
      ret = 1
      ret = ret * kaijo(n) % MOD
      ret = ret * gyaku_kaijo(r) % MOD
      ret = ret * gyaku_kaijo(n - r) % MOD
      return ret
  
  
  ######Factorization######
  def factorization(n):
      arr = []
      temp = n
      for i in range(2, int(-(-(n**0.5) // 1)) + 1):
          if temp % i == 0:
              cnt = 0
              while temp % i == 0:
                  cnt += 1
                  temp //= i
              arr.append([i, cnt])
      if temp != 1:
          arr.append([temp, 1])
  
      if arr == []:
          arr.append([n, 1])
      return arr
  
  
  #####LCM#####
  def lcm(a, b):
      return a * b // gcd(a, b)
  
  
  #############
  # Main Code #
  #############
  
  X, A, B = inputIL()
  
  if B <= A:
      print("delicious")
  elif B <= A + X:
      print("safe")
  else:
      print("dangerous")
  
problem_description: 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.
samples: [{"input": "4 3 6", "output": "safe\n    \n\nHe ate the food three days after the \"best-by\" date. It was not delicious or\nharmful for him.\n\n* * *"}, {"input": "6 5 1", "output": "delicious\n    \n\nHe ate the food by the \"best-by\" date. It was delicious for him.\n\n* * *"}, {"input": "3 7 12", "output": "dangerous\n    \n\nHe ate the food five days after the \"best-by\" date. It was harmful for him."}]