output_description: Print the minimum possible area of a rectangle that satisfies the condition.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N K  
      x_1 y_1
      :  
      x_{N} y_{N}
attempt: N, K = map(int, input().split())
  A = [list(map(int, input().split())) for i in range(N)]
  B, C = zip(*A)
  S = 10**36
  for left in B:
      for right in B:
          for up in C:
              for down in C:
                  if left < right and down < up:
                      cnt = 0
                      for x, y in A:
                          if left <= x <= right and down <= y <= up:
                              cnt += 1
                      if cnt >= K:
                          S = min(S, (right - left) * (up - down))
  print(S)
  
problem_description: Statement
  
  We have N points in a two-dimensional plane.  
  The coordinates of the i-th point (1 \leq i \leq N) are (x_i,y_i).  
  Let us consider a rectangle whose sides are parallel to the coordinate axes
  that contains K or more of the N points in its interior.  
  Here, points on the sides of the rectangle are considered to be in the
  interior.  
  Find the minimum possible area of such a rectangle.
samples: [{"input": "4 4\n    1 4\n    3 3\n    6 2\n    8 1", "output": "21\n    \n\nOne rectangle that satisfies the condition with the minimum possible area has\nthe following vertices: (1,1), (8,1), (1,4) and (8,4).  \nIts area is (8-1) \u00d7 (4-1) = 21.\n\n* * *"}, {"input": "4 2\n    0 0\n    1 1\n    2 2\n    3 3", "output": "1\n    \n\n* * *"}, {"input": "4 3\n    -1000000000 -1000000000\n    1000000000 1000000000\n    -999999999 999999999\n    999999999 -999999999", "output": "3999999996000000001\n    \n\nWatch out for integer overflows."}]