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 main():
      N, K = map(int, input().split())
      l = []
      xl = []
      yl = []
      for _ in range(N):
          x, y = map(int, input().split())
          l.append((x, y))
          xl.append(x)
          yl.append(y)
      xl.sort()
      yl.sort()
      xd = {}
      dx = {}
      t = 0
      p = xl[0]
      for i in xl:
          if i != p:
              t += 1
          xd[i] = t
          dx[t] = i
          p = i
      yd = {}
      dy = {}
      t = 0
      p = yl[0]
      for i in yl:
          if i != p:
              t += 1
          yd[i] = t
          dy[t] = i
          p = i
      l2 = []
      for x, y in l:
          l2.append((xd[x], yd[y]))
      m = 10**100
      for si in range(len(xd) - 1):
          for ei in range(si + 1, len(xd)):
              for sj in range(len(yd) - 1):
                  for ej in range(sj + 1, len(yd)):
                      t = 0
                      for x, y in l2:
                          if si <= x <= ei and sj <= y <= ej:
                              t += 1
                      if t >= K:
                          m = min(m, (dx[ei] - dx[si]) * (dy[ej] - dy[sj]))
      return m
  
  
  print(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."}]