output_description: Print the maximum possible number of times he waked up early during the
  recorded period.
  
  * * *
input_description: The input is given from Standard Input in the following format:
  
      
      
      N
      a_1 b_1
      a_2 b_2
      :
      a_N b_N
attempt: n = int(input())
  x, num = [], 0
  for i in range(n):
      a, b = (int(j) for j in input().split())
      x.append((num + a) % 86400)
      num = (num + a + b) % 86400
  x, ans = sorted(x), 0
  from bisect import bisect
  
  for i in range(n):
      ans = max(ans, bisect(x, x[i] + 10800) - i)
  print(ans)
  
problem_description: Statement
  
  Takahashi recorded his daily life for the last few days as a integer sequence
  of length 2N, as follows:
  
    * a_1, b_1, a_2, b_2, ... , a_N, b_N
  
  This means that, starting from a certain time T, he was:
  
    * sleeping for exactly a_1 seconds
    * then awake for exactly b_1 seconds
    * then sleeping for exactly a_2 seconds
    * :
    * then sleeping for exactly a_N seconds
    * then awake for exactly b_N seconds
  
  In this record, he waked up N times.
  
  Takahashi is wondering how many times he waked up early during the recorded
  period.
  
  Here, he is said to _wake up early_ if he wakes up between 4:00 AM and 7:00
  AM, inclusive.
  
  If he wakes up more than once during this period, each of these awakenings is
  counted as waking up early.
  
  Unfortunately, he forgot the time T.
  
  Find the maximum possible number of times he waked up early during the
  recorded period.
  
  For your information, a day consists of 86400 seconds, and the length of the
  period between 4:00 AM and 7:00 AM is 10800 seconds.
samples: [{"input": "3\n    28800 57600\n    28800 57600\n    57600 28800", "output": "2\n    \n\n* * *"}, {"input": "10\n    28800 57600\n    4800 9600\n    6000 1200\n    600 600\n    300 600\n    5400 600\n    6000 5760\n    6760 2880\n    6000 12000\n    9000 600", "output": "5"}]