#include<bits/stdc++.h>
using namespace std;
 
template <class T1, class T2>
ostream& operator << (ostream& out, const pair <T1, T2> p)
{
        out << '(' << p.first << ',' << p.second << ')';
            return out;
}
 
template <class T1, class T2>
istream& operator >> (istream& in, pair<T1, T2> &p)
{
        in >> p.first >> p.second;
            return in;
}
 
template <class T>
istream& operator >> (istream& in, vector<T> &v)
{
        for (T &x : v)
                    in >> x;
            return in;
}
 
template <class T>
ostream& operator << (ostream& out, const vector<vector<T> > &v)
{
        for (const vector<T> &x : v)
                    out << x << '\n';
            return out;
}
 
template <class T>
ostream& operator << (ostream& out, const vector<T> &v)
{
        for (const T &x : v)
                    out << x << ' ';
            return out;
}

template <class T>
ostream& operator << (ostream& out,const set<T> &s)
{
        for (const T &x : s)
                out << x << ' ';
            return out;
}
 
 
#define ll long long
#define lf long double
#define pb push_back
#define mp make_pair
#define F first
#define S second
typedef pair <ll,ll > ii;
typedef vector <ll> vi;
typedef vector <ii> vii;
typedef vector <bool> vb;
typedef vector <vector <ll> > vv;
typedef vector <vector <vector<ll> > > vvv;
typedef vector <string> vs;
typedef vector <lf> vf;
#define sz(x) (ll)(x).size()
#define tr1(x) cerr << #x << ": " << x << nl
#define tr2(x, y) cerr << #x << ": " << x << " | " << #y << ": " << y << nl
#define tr3(x,y,z) cerr<<#x<<": "<<x<<" | "<<#y<<": "<<y<<" | "<<#z<<": "<<z<<nl
#define tr4(x,y,z,w) cerr<<#x<<": "<<x<<" | "<<#y<<": "<<y<<" | "<<#z<<": "<<z<<" | "<<#w<<": "<<w<<nl
#define trv(a) cerr<<#a<<": ";for(ll zz=0;zz<sz(a);zz++) cerr<<a[zz]<<" ";cerr<<nl
#define trset(s) cerr<<#s<<": ";for(auto &i:s) cerr<<i<<" ";cerr<<nl
#define epsilon 0.00000001L
#define inf 9999999999999999ll// ~ 10^16
#define nl endl
#define all(x) x.begin(), x.end()
#define r_all(x) x.rbegin(), x.rend()
#define fast()  ios_base::sync_with_stdio(false);cin.tie(NULL)
#define mod 1000000007ll
#define modulo 998244353ll
ll power(ll a,ll b){return b?power(a*a%mod,b/2)*(b%2?a:1)%mod:1;}

int main()
{
    fast();
    ll n,k1;
    cin>>n>>k1;
    unsigned ll ans=ULLONG_MAX;
    vi x(n);
    vi y(n);
    for(ll i=0;i<n;i++)
        cin>>x[i]>>y[i];
    if(k1==2)
    {
        for(ll i=0;i<n;i++)
        {
            for(ll j=i+1;j<n;j++)
            {
                ans=min(ans,(unsigned ll)abs(x[i]-x[j])*abs(y[i]-y[j]));
            }
        }
    }
    else if(k1==3)
    {
        for(ll i=0;i<n;i++)
        {
            for(ll j=i+1;j<n;j++)
            {
                for(ll k=j+1;k<n;k++)
                {
                    ll x1=min(x[i],min(x[j],x[k]));
                    ll x2=max(x[i],max(x[j],x[k]));
                    
                    ll y1=min(y[i],min(y[j],y[k]));
                    ll y2=max(y[i],max(y[j],y[k]));
                    ans=min(ans,(unsigned long long)(x2-x1)*(y2-y1));
                }
            }
        }
    }
    else
    {
        for(ll i=0;i<n;i++)
        {
            for(ll j=i+1;j<n;j++)
            {
                for(ll k=j+1;k<n;k++)
                {
                    for(ll m=k+1;m<n;m++)
                    {
                        ll x1=min(min(x[i],x[j]),min(x[k],x[m]));
                        ll x2=max(max(x[i],x[j]),max(x[k],x[m]));
                        
                        ll y1=min(min(y[i],y[j]),min(y[k],y[m]));
                        ll y2=max(max(y[i],y[j]),max(y[k],y[m]));
                        
                        ll count=0;
                        for(ll p=0;p<n;p++)
                        {
                            if(x1<=x[p] && x2>=x[p] && y1<=y[p] && y2>=y[p])
                            {
                                count++;
                            }
                        }
                        if(count>=k1)
                            ans=min(ans,(unsigned ll)(x2-x1)*(y2-y1));
                    }
                }
            }
        }
    }
    cout<<ans<<nl;
}


Measured memory_bytes: 3636