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: from collections import deque
  import sys
  
  sys.setrecursionlimit(10**6)
  int1 = lambda x: int(x) - 1
  p2D = lambda x: print(*x, sep="\n")
  
  
  def II():
      return int(sys.stdin.readline())
  
  
  def MI():
      return map(int, sys.stdin.readline().split())
  
  
  def LI():
      return list(map(int, sys.stdin.readline().split()))
  
  
  def LLI(rows_number):
      return [LI() for _ in range(rows_number)]
  
  
  def SI():
      return sys.stdin.readline()[:-1]
  
  
  def main():
      n, k = MI()
      xx = set()
      yy = set()
      xy = []
      for _ in range(n):
          x, y = MI()
          xy.append((x, y))
          xx.add(x)
          yy.add(y)
      xy.sort()
      xx = list(sorted(xx))
      yy = list(sorted(yy))
      xn = len(xx)
      yn = len(yy)
      ans = 10**20
      for t in range(yn):
          y2 = yy[t]
          for b in range(t):
              y1 = yy[b]
              r = -1
              s = 0
              i = j = 0
              for l, x1 in enumerate(xx):
                  while i < n and xy[i][0] < x1:
                      if y1 <= xy[i][1] <= y2:
                          s -= 1
                      i += 1
                  while s < k and r + 1 < xn:
                      r += 1
                      x2 = xx[r]
                      while j < n and xy[j][0] <= x2:
                          if y1 <= xy[j][1] <= y2:
                              s += 1
                          j += 1
                  if s >= k:
                      cur = (x2 - x1) * (y2 - y1)
                      if cur < ans:
                          ans = cur
      print(ans)
  
  
  main()
  
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."}]