output_description: Print the area of this yard excluding the roads (in square yards).
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      A B
attempt: n, m, q = map(int, input().split())
  rails = [tuple(map(int, input().split())) for i in range(m)]
  qs = [tuple(map(int, input().split())) for i in range(q)]
  enuq = list(enumerate(qs))
  
  enuq.sort(key=lambda x: x[1][0])
  ansli = [0 for i in range(q)]
  
  
  for i, (p, q) in enuq:
      removelist = []
      for j, (l, r) in enumerate(rails):
          if p <= l and r <= q:
              ansli[i] = ansli[i] + 1
          elif l < p:
              removelist.append(j)
      for jj in removelist:
          rails.pop(jj)
  
  
  for a in ansli:
      print(a)
  
problem_description: Statement
  
  There is a farm whose length and width are A yard and B yard, respectively. A
  farmer, John, made a vertical road and a horizontal road inside the farm from
  one border to another, as shown below: (The gray part represents the roads.)
  
  ![ ](https://img.atcoder.jp/ghi/27d063746b460f1132b6a99aa535a562.png)
  
  What is the area of this yard excluding the roads? Find it.
samples: [{"input": "2 2", "output": "1\n    \n\nIn this case, the area is 1 square yard.\n\n* * *"}, {"input": "5 7", "output": "24\n    \n\nIn this case, the area is 24 square yards."}]