output_description: Replace the first four characters in S with `2018` and print it.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      S
attempt: import math
  
  
  def find_argmax(num_list):
      argmax = sorted(enumerate(num_list), key=lambda x: x[1])[-1][0]
      return argmax
  
  
  def find_all_more_than(threshold, num_list):
      indices = [idx for idx, num in enumerate(num_list) if num > threshold]
      return indices
  
  
  def read_input():
      initial_inputs = input().split(" ")
      N = int(initial_inputs[0])
      H = int(initial_inputs[1])
      a_list = []
      b_list = []
      for _ in range(N):
          inputs = input().split(" ")
          a = int(inputs[0])
          b = int(inputs[1])
          a_list.append(a)
          b_list.append(b)
      return N, H, a_list, b_list
  
  
  # TLE
  def searchA(N, H, a_list, b_list):
      # initialize used_indices
      used_indices = [False for b in b_list]
  
      # initialize search_area
      search_area = [b for b in b_list]
  
      # count how many times
      times_count = 0
  
      while H > 0:
          # search
          idx = find_argmax(search_area)
  
          # check
          if used_indices[idx]:
              # calculate rest and finish
              rest_count = math.ceil(H / search_area[idx])
              return times_count + rest_count
  
          # attack
          H -= search_area[idx]
  
          # change
          search_area[idx] = a_list[idx]
          used_indices[idx] = True
  
          # count
          times_count += 1
  
      return times_count
  
  
  def searchB(N, H, a_list, b_list):
      # initialize used_indices
      used_indices = [False] * N
  
      # initialize search_area
      search_area = [b for b in b_list]
  
      # count how many times
      times_count = 0
  
      # pick up b indices higher than max(a_list)
      higher_b_indices = find_all_more_than(max(a_list), b_list)
      for idx in higher_b_indices:
          if not H > 0:
              return times_count
  
          used_indices[idx] = True
  
          # attack
          H -= search_area[idx]
          times_count += 1
  
          # change
          search_area[idx] = a_list[idx]
          used_indices[idx] = True
  
      while H > 0:
          # search
          idx = find_argmax(search_area)
  
          # check
          if used_indices[idx]:
              # calculate rest and finish
              rest_count = math.ceil(H / search_area[idx])
              return times_count + rest_count
  
          # attack
          H -= search_area[idx]
          times_count += 1
  
          # change
          search_area[idx] = a_list[idx]
          used_indices[idx] = True
  
      return times_count
  
  
  def main():
      # read input
      N, H, a_list, b_list = read_input()
  
      # search
      times_count = searchB(N, H, a_list, b_list)
  
      # output
      print(times_count)
  
  
  if __name__ == "__main__":
      main()
  
problem_description: Statement
  
  On some day in January 2018, Takaki is writing a document. The document has a
  column where the current date is written in `yyyy/mm/dd` format. For example,
  January 23, 2018 should be written as `2018/01/23`.
  
  After finishing the document, she noticed that she had mistakenly wrote `2017`
  at the beginning of the date column. Write a program that, when the string
  that Takaki wrote in the date column, S, is given as input, modifies the first
  four characters in S to `2018` and prints it.
samples: [{"input": "2017/01/07", "output": "2018/01/07\n    \n\n* * *"}, {"input": "2017/01/31", "output": "2018/01/31"}]