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: def getN():
      return int(input())
  
  
  def getNM():
      return map(int, input().split())
  
  
  def getList():
      return list(map(int, input().split()))
  
  
  import copy
  
  n, k = getList()
  buff = []
  for i in range(n):
      buff.append(getList())
  
  
  def calc(width, cutbuf, k):
      nn = len(cutbuf)
      cutbuf.sort(key=lambda x: x[1])
      ret = 10**19
      for ii in range(nn - k + 1):
          tmptmp = abs(cutbuf[ii][1] - cutbuf[ii + k - 1][1])
          # print("here")
          if ret > tmptmp:
              # print("here")
              ret = tmptmp
      # print(ret, cutbuf)
      return ret * width
  
  
  buff.sort()
  ans = 10**19
  for i in range(n):
      for j in range(i + 1, n):
          width = abs(buff[i][0] - buff[j][0])
          tmp = calc(width, buff[i : j + 1], k)
  
          if ans > tmp:
              ans = tmp
  
  print(ans)
  
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."}]