output_description: For each data set, you are requested to print one line containing the maximum
  possible number of persimmon trees that can be included in an estate of the
  given size.
input_description: The input consists of multiple data sets. Each data set is given in the
  following format.
  
  > _N_  
  >  _W_` `_H_  
  >  _x_ 1` `_y_ 1  
  >  _x_ 2` `_y_ 2  
  >  ...  
  >  _x_ _N_` `_y_ _N_  
  >  _S_` `_T_  
  >
  
  _N_ is the number of persimmon trees, which is a positive integer less than
  500. _W_ and _H_ are the width and the height of the entire field
  respectively. You can assume that both _W_ and _H_ are positive integers whose
  values are less than 100. For each _i_ (1 <= _i_ <= _N_), _x_ _i_ and _y_ _i_
  are coordinates of the _i_ -th persimmon tree in the grid. Note that the
  origin of each coordinate is 1. You can assume that 1 <= _x_ _i_ <= _W_ and 1
  <= _y_ _i_ <= _H_ , and no two trees have the same positions. But you should
  not assume that the persimmon trees are sorted in some order according to
  their positions. Lastly, _S_ and _T_ are positive integers of the width and
  height respectively of the estate given by the lord. You can also assume that
  1 <= _S_ <= _W_ and 1 <= _T_ <= _H_.
  
  The end of the input is indicated by a line that solely contains a zero.
attempt: trial = int(input())
  while True:
      area = [int(n) for n in input().split(" ")]
      trees = []
      for t in range(trial):
          trees.append(int(n) for n in input().split(" "))
      cnt, answer = 0, 0
      trees = sorted(trees, key=lambda x: (x[0], x[1]))
      building = [int(n) for n in input().split(" ")]
      for x in range(1, 1 + area[0] - building[0]):
          for y in range(1, 1 + area[1] - building[1]):
              cnt = 0
              for tree in trees:
                  if x <= tree[0] <= x + building[0] and y <= tree[1] <= y + building[1]:
                      cnt += 1
                  elif x + building[0] < tree[0] and y + building[1] < tree[1]:
                      if answer < cnt:
                          answer = cnt
                          break
              else:
                  if answer < cnt:
                      answer = cnt
      else:
          print(answer)
          trial = int(input())
          if trial == 0:
              break
  
problem_description: Get Many Persimmon Trees
  
  Seiji Hayashi had been a professor of the Nisshinkan Samurai School in the
  domain of Aizu for a long time in the 18th century. In order to reward him for
  his meritorious career in education, Katanobu Matsudaira, the lord of the
  domain of Aizu, had decided to grant him a rectangular estate within a large
  field in the Aizu Basin. Although the size (width and height) of the estate
  was strictly specified by the lord, he was allowed to choose any location for
  the estate in the field. Inside the field which had also a rectangular shape,
  many Japanese persimmon trees, whose fruit was one of the famous products of
  the Aizu region known as 'Mishirazu Persimmon', were planted. Since persimmon
  was Hayashi's favorite fruit, he wanted to have as many persimmon trees as
  possible in the estate given by the lord.
  
  For example, in Figure 1, the entire field is a rectangular grid whose width
  and height are 10 and 8 respectively. Each asterisk (*) represents a place of
  a persimmon tree. If the specified width and height of the estate are 4 and 3
  respectively, the area surrounded by the solid line contains the most
  persimmon trees. Similarly, if the estate's width is 6 and its height is 4,
  the area surrounded by the dashed line has the most, and if the estate's width
  and height are 3 and 4 respectively, the area surrounded by the dotted line
  contains the most persimmon trees. Note that the width and height cannot be
  swapped; the sizes 4 by 3 and 3 by 4 are different, as shown in Figure 1\.
  
  ![](https://judgeapi.u-aizu.ac.jp/resources/images/IMAGE1_trees)  
  ---  
  Figure 1: Examples of Rectangular Estates  
    
  Your task is to find the estate of a given size (width and height) that
  contains the largest number of persimmon trees.
samples: [{"input": "10 8\n    2 2\n    2 5\n    2 7\n    3 3\n    3 8\n    4 2\n    4 5\n    4 8\n    6 4\n    6 7\n    7 5\n    7 8\n    8 1\n    8 4\n    9 6\n    10 3\n    4 3\n    8\n    6 4\n    1 2\n    2 1\n    2 4\n    3 4\n    4 2\n    5 3\n    6 1\n    6 2\n    3 2\n    0", "output": "3"}]