#include<bits/stdc++.h>
using namespace std;
int n,k,x[55],y[55],ans=0x3f3f3f3f;
struct jx{
	int lx,ly,rx,ry;
	bool flag;
	void add(int x,int y) 
    {
		if(!flag) 
        {
			lx=x;
            rx=x;
			ly=y;
            ry=y;
			flag=1;
		} 
        else 
        {
			if(x<lx) lx=x;
			else if(x>rx) rx=x;
			if(y>ly) ly=y;
			else if(y<ry) ry=y;
		}
	}
	bool injx(int x,int y) const
    {
		return lx<=x&&x<=rx&&ry<=y&&y<=ly;
	}
	int operator()() 
    {
		if(!flag) return 0;
		return (rx-lx)*(ly-ry);
	}
	bool operator*(const jx&o) 
    {
		if(!flag||!o.flag) return 0;
		return o.injx(lx,ly)||o.injx(lx,ry)||o.injx(rx,ly)||o.injx(rx,ry);
	}
}a[5];
bool check() 
{
	for(int i=1;i<=k;i++)
	{
		for(int j=i+1;j<=k;j++)
		{
			if(a[i]*a[j]) return 0;
		}
	}
	return 1;
}
void dfs(int d,int area) 
{
	if(area>=ans) return;
	if(d==n+1) 
    {
		if(check())
		{
			if(ans>area) ans=area;
		}
		return;
	}
	jx now;
	for(int j=1;j<=k;j++) 
    {
		now=a[j];
		a[j].add(x[d],y[d]);
		dfs(d+1,area-now()+a[j]());
		a[j]=now;
	}
}
int main() 
{
    freopen("jxfg.in","r",stdin);
    freopen("jxfg.out","w",stdout);
	scanf("%d%d",&n,&k);
	for(int i=1;i<=n;i++)
	{
		scanf("%d%d",&x[i],&y[i]);
    }
	dfs(1,0);
	printf("%d",ans);
	return 0;
}