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 sys
  
  
  def ii():
      return int(sys.stdin.readline())
  
  
  def mi():
      return map(int, sys.stdin.readline().split())
  
  
  def li():
      return list(map(int, sys.stdin.readline().split()))
  
  
  def li2(N):
      return [list(map(int, sys.stdin.readline().split())) for i in range(N)]
  
  
  def dp2(ini, i, j):
      return [[ini] * i for i2 in range(j)]
  
  
  def dp3(ini, i, j, k):
      return [[[ini] * i for i2 in range(j)] for i3 in range(k)]
  
  
  import bisect
  
  
  N, H = mi()
  A = [0] * N
  B = [0] * N
  for i in range(N):
      A[i], B[i] = mi()
  
  B = sorted(B)
  a = max(A)
  m = bisect.bisect_left(B, a)
  """
  s = 1
  e = N
  m = (s+e)//2
  pre_m = 0
  while True:
      m = (s+e)//2
      if B[m-1] > a:
          e = m
      elif B[m-1] <= a:
          s = m
      if s==e:
          m -= 1
          break
      #else:
          #break
      if e-s==1 and pre_m==m:
          break
      pre_m = m
  """
  rem = H - sum(B[m:])
  if rem >= 0:
      print((N - m) + rem // a + (rem % a == 0))
  else:
      for i in range(m, N):
          rem += B[i]
          if rem >= 0:
              print(N - i)
  
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"}]