output_description: Print Q lines. The i-th line should contain the number of the trains that runs
  **strictly within** the section from City p_i to City q_i.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N M Q
      L_1 R_1
      L_2 R_2
      :
      L_M R_M
      p_1 q_1
      p_2 q_2
      :
      p_Q q_Q
attempt: class Cumsum2d(object):
      def __init__(self, a):
          self.a = a
          self.h = len(a)
          self.w = len(a[0])
          self._cumsum = [[0 for _ in range(self.w + 1)] for _ in range(self.h + 1)]
          self._preprocess()
  
      def _preprocess(self):
          for i in range(1, self.h + 1):
              for j in range(1, self.w + 1):
                  self._cumsum[i][j] = (
                      self.a[i - 1][j - 1]
                      + self._cumsum[i][j - 1]
                      + self._cumsum[i - 1][j]
                      - self._cumsum[i - 1][j - 1]
                  )
  
      def query(self, h1, h2, w1, w2):
          return (
              self._cumsum[h2][w2]
              - self._cumsum[h1][w2]
              - self._cumsum[h2][w1]
              + self._cumsum[h1][w1]
          )
  
  
  if __name__ == "__main__":
      N, M, Q = [int(x) for x in input().split(" ")]
      # L = [0 for _ in range(N + 2)]
      count = [[0 for _ in range(N + 1)] for _ in range(N + 1)]
      for _ in range(M):
          l, r = [int(x) for x in input().split(" ")]
          count[l][r] += 1
  
      cumsum = Cumsum2d(count)
      for _ in range(Q):
          p, q = [int(x) for x in input().split(" ")]
          print(cumsum.query(p, q + 1, p, q + 1))
  
problem_description: Statement
  
  In Takahashi Kingdom, there is a east-west railroad and N cities along it,
  numbered 1, 2, 3, ..., N from west to east. A company called _AtCoder Express_
  possesses M trains, and the train i runs from City L_i to City R_i (it is
  possible that L_i = R_i). Takahashi the king is interested in the following Q
  matters:
  
    * The number of the trains that runs **strictly within** the section from City p_i to City q_i, that is, the number of trains j such that p_i \leq L_j and R_j \leq q_i.
  
  Although he is genius, this is too much data to process by himself. Find the
  answer for each of these Q queries to help him.
samples: [{"input": "2 3 1\n    1 1\n    1 2\n    2 2\n    1 2", "output": "3\n    \n\nAs all the trains runs within the section from City 1 to City 2, the answer to\nthe only query is 3.\n\n* * *"}, {"input": "10 3 2\n    1 5\n    2 8\n    7 10\n    1 7\n    3 10", "output": "1\n    1\n    \n\nThe first query is on the section from City 1 to 7. There is only one train\nthat runs strictly within that section: Train 1. The second query is on the\nsection from City 3 to 10. There is only one train that runs strictly within\nthat section: Train 3.\n\n* * *"}, {"input": "10 10 10\n    1 6\n    2 9\n    4 5\n    4 7\n    4 7\n    5 8\n    6 6\n    6 7\n    7 9\n    10 10\n    1 8\n    1 9\n    1 10\n    2 8\n    2 9\n    2 10\n    3 8\n    3 9\n    3 10\n    1 10", "output": "7\n    9\n    10\n    6\n    8\n    9\n    6\n    7\n    8\n    10"}]