output_description: Print the value: "the sum of the happiness Takahashi earns in the end" minus
  "the sum of the happiness Aoki earns in the end".
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      A_1 B_1
      :
      A_N B_N
attempt: import numpy as np
  
  
  class Person:
      def __init__(self, list_score_my, list_score_other, list_eatable):
          self.list_score_my = list_score_my
          self.list_score_other = list_score_other
          self.list_eatable = list_eatable
          self.eatable = True
          self.score_sum = 0
  
      # other
      def get_score_max_other(self):
          return np.max(self.list_score_other)
  
      def get_score_max_other_eatable(self):
          return np.max(self.list_score_other * self.list_eatable)
  
      def get_index_of_score_max_other_eatable(self):
          return np.where(self.list_score_other == self.get_score_max_other_eatable())
  
      def is_other_has_same_max_score(self):
          flag = 0
          score_other_max = np.max(self.list_score_other)
          for i in self.list_score_other:
              if self.list_score_other[i] == self.score_other_max:
                  flag += 1
  
          if flag > 1:
              return True
          else:
              return False
  
      # my
      def get_score_max_my(self):
          return np.max(self.list_score_my)
  
      def get_score_max_my_eatable(self):
          return np.max(self.list_score_my * self.list_eatable)
  
      def get_index_of_score_max_my_eatable(self):
          return np.where(self.list_score_my == self.get_score_max_my_eatable())
  
      def is_i_have_same_max_score(self):
          flag = 0
          self.score_my_max = np.max(self.list_score_my)
          for i in range(len(self.list_score_my)):
              if self.list_score_my[i] == self.score_my_max:
                  flag += 1
          if flag > 1:
              return True
          else:
              return False
  
      def eat(self, index):
          self.list_eatable[index] = False
          self.score_sum += self.list_score_my[index]
  
      def print_score(self):
          print(self.list_score_my)
  
  
  def get_data(ryouri_goukei_num):
      list_score_a = np.empty(ryouri_goukei_num)
      list_score_b = np.empty(ryouri_goukei_num)
      list_ryouri_is_eatable = np.empty(ryouri_goukei_num)
  
      for i in range(ryouri_goukei_num):
          inputData = input()
          splitData = inputData.split()
          a_data = int(splitData[0])
          b_data = int(splitData[1])
          list_score_a[i] = a_data
          list_score_b[i] = b_data
          list_ryouri_is_eatable[i] = True
  
      return list_score_a, list_score_b, list_ryouri_is_eatable
  
  
  def main():
      ryouri_goukei_num = int(input())
      list_score_a, list_score_b, list_ryouri_is_eatable = get_data(ryouri_goukei_num)
  
      takahashi = Person(list_score_a, list_score_b, list_ryouri_is_eatable)
      aoki = Person(list_score_b, list_score_a, list_ryouri_is_eatable)
  
      takahashi.print_score()
      aoki.print_score()
  
      for i in range(ryouri_goukei_num):
          if takahashi.eatable:
              if takahashi.is_i_have_same_max_score():
                  takahashi.eat(takahashi.get_index_of_score_max_other_eatable())
              else:
                  takahashi.eat(takahashi.get_index_of_score_max_my_eatable())
  
              takahashi.eatable = False
              aoki.eatable = True
              list_ryouri_is_eatable = takahashi.eatable
              continue
  
          if aoki.eatable:
              if aoki.is_i_have_same_max_score():
                  aoki.eat(aoki.get_index_of_score_max_other_eatable())
              else:
                  aoki.eat(aoki.get_index_of_score_max_my_eatable())
  
              takahashi.eatable = True
              aoki.eatable = False
              list_ryouri_is_eatable = aoki.eatable
              continue
  
      print(int(takahashi.score_sum - aoki.score_sum))
  
  
  main()
  
problem_description: Statement
  
  There are N dishes of cuisine placed in front of Takahashi and Aoki. For
  convenience, we call these dishes Dish 1, Dish 2, ..., Dish N.
  
  When Takahashi eats Dish i, he earns A_i points of _happiness_ ; when Aoki
  eats Dish i, she earns B_i points of happiness.
  
  Starting from Takahashi, they alternately choose one dish and eat it, until
  there is no more dish to eat. Here, both of them choose dishes so that the
  following value is maximized: "the sum of the happiness he/she will earn in
  the end" minus "the sum of the happiness the other person will earn in the
  end".
  
  Find the value: "the sum of the happiness Takahashi earns in the end" minus
  "the sum of the happiness Aoki earns in the end".
samples: [{"input": "3\n    10 10\n    20 20\n    30 30", "output": "20\n    \n\nIn this sample, both of them earns 10 points of happiness by eating Dish 1, 20\npoints by eating Dish 2, and 30 points by eating Dish 3.\n\nIn this case, since Takahashi and Aoki have the same \"taste\", each time they\nwill choose the dish with which they can earn the greatest happiness. Thus,\nfirst Takahashi will choose Dish 3, then Aoki will choose Dish 2, and finally\nTakahashi will choose Dish 1, so the answer is (30 + 10) - 20 = 20.\n\n* * *"}, {"input": "3\n    20 10\n    20 20\n    20 30", "output": "20\n    \n\nIn this sample, Takahashi earns 20 points of happiness by eating any one of\nthe dishes 1, 2 and 3, but Aoki earns 10 points of happiness by eating Dish 1,\n20 points by eating Dish 2, and 30 points by eating Dish 3.\n\nIn this case, since only Aoki has likes and dislikes, each time they will\nchoose the dish with which Aoki can earn the greatest happiness. Thus, first\nTakahashi will choose Dish 3, then Aoki will choose Dish 2, and finally\nTakahashi will choose Dish 1, so the answer is (20 + 20) - 20 = 20.\n\n* * *"}, {"input": "6\n    1 1000000000\n    1 1000000000\n    1 1000000000\n    1 1000000000\n    1 1000000000\n    1 1000000000", "output": "-2999999997\n    \n\nNote that the answer may not fit into a 32-bit integer."}]