text: import math
  
  n = int(input())
  prev_t = 0
  prev_d = 0
  greatest = 0
  sp = 0
  
  for i in range(n):
      t, d = map(int, input().split())
      if t != 0 and d != 0:
          sp = math.floor((d-prev_d)/(t-prev_t))
          if sp > greatest:
              greatest = sp
  
      prev_t = t
      prev_d = d
  
  print(greatest)
          