output_description: Print the answer.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      A_1 B_1
      A_2 B_2
      :
      A_N B_N
attempt: how_many = int(input())
  least, biggest = [], []
  for i in range(how_many):
      nums = input().split()
      nums = [int(num) for num in nums]
      least.append(nums[0])
      biggest.append(nums[1])
  least.sort()
  biggest.sort()
  if how_many % 2 == 1:
      print(biggest[int((how_many - 1) / 2)] - least[int((how_many - 1) / 2)] + 1)
  else:
      l = (least[int(how_many / 2)] + least[int(how_many / 2 - 1)]) / 2
      b = (biggest[int(how_many / 2)] + biggest[int(how_many / 2 - 1)]) / 2
      print(int((b - l) / 0.5 + 1))
  
problem_description: Statement
  
  There are N integers X_1, X_2, \cdots, X_N, and we know that A_i \leq X_i \leq
  B_i. Find the number of different values that the median of X_1, X_2, \cdots,
  X_N can take.
samples: [{"input": "2\n    1 2\n    2 3", "output": "3\n    \n\n  * If X_1 = 1 and X_2 = 2, the median is \\frac{3}{2};\n\n  * if X_1 = 1 and X_2 = 3, the median is 2;\n\n  * if X_1 = 2 and X_2 = 2, the median is 2;\n\n  * if X_1 = 2 and X_2 = 3, the median is \\frac{5}{2}.\n\nThus, the median can take three values: \\frac{3}{2}, 2, and \\frac{5}{2}.\n\n* * *"}, {"input": "3\n    100 100\n    10 10000\n    1 1000000000", "output": "9991"}]