Problem: 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.

Constraints

* 2 \leq K \leq N \leq 50
* -10^9 \leq x_i,y_i \leq 10^9 (1 \leq i \leq N)
* x_i≠x_j (1 \leq i<j \leq N)
* y_i≠y_j (1 \leq i<j \leq N)
* All input values are integers. (Added at 21:50 JST)

Input

Input is given from Standard Input in the following format:


N K
x_1 y_1
:
x_{N} y_{N}


Output

Print the minimum possible area of a rectangle that satisfies the condition.

Examples

Input

4 4
1 4
3 3
6 2
8 1


Output

21


Input

4 2
0 0
1 1
2 2
3 3


Output

1


Input

4 3
-1000000000 -1000000000
1000000000 1000000000
-999999999 999999999
999999999 -999999999


Output

3999999996000000001

Solution (in PYTHON):

Solution:
N, K = map(int, raw_input().split())
ps = []
for i in xrange(N):
  ps.append(map(int, raw_input().split()))

xsorted = zip(*sorted(ps, key=lambda p: p[0]))[0]
ysorted = zip(*sorted(ps, key=lambda p: p[1]))[1]

ans = float('inf')
for i in xrange(N):
  bottom = ysorted[i]
  for j in xrange(i+K-1, N):
    top = ysorted[j]
    for k in xrange(N):
      if k+K-1 >= N:
        break
      right = xsorted[k]
      # 2 bun tansaku
      f, t = k+K-1, N
      sol = None
      while True:
        mid = (f+t)//2
        left = xsorted[mid]
        c = 0
        for p in ps:
          if right <= p[0] <= left and bottom <= p[1] <= top:
            c += 1
            if c >= K: break
        else:
          if f+1 >= t:
            break
          f = mid
          continue
        sol = mid
        if f+1 >= t:
          break
        t = mid
      if sol:
        area = (xsorted[sol] - right) * (top - bottom)
        if area < ans:
          ans = area

print ans