#define TEST_MODE true

#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES

#include "bits/stdc++.h"
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define rep2(i, a, b) for (int i = (a); i < (int)(b); ++i)
#define rrep(i, n) for (int i = (n)-1; i >= 0; --i)
#define rrep2(i, a, b) for (int i = (a)-1; i >= (int)b; --i)
#define range(i, a, b, c) for (int i = a;             \
                                   c > 0 ? i < b : i > b; \
                                   i += c)
#define chmax(a, b) (a = (a) < (b) ? (b) : (a))
#define chmin(a, b) (a = (a) > (b) ? (b) : (a))
using ll = long long;
using ull = unsigned long long;
using ld = long double;
#define all(a) begin(a), end(a)
#define ifnot(a) if (not(a))
#define int long long

#ifdef LOCAL_ENV

#if TEST_MODE == true
const bool test = true;
#define dump(x) cerr << #x << " = " << (x)
#define dumpl(x) dump(x) << endl
#else
const bool test = false;
#define dump(x) 
#define dumpl(x)
#endif

#else
const bool test = false;
#define dump(x) 
#define dumpl(x)
#endif

int dx[] = { 1, 0, -1, 0 };
int dy[] = { 0, 1, 0, -1 };
const int INF = (int)1 << 62;
const ll INFL = (ll)1 << 60;
ll mod_n = (int)1e9 + 7;
const double eps = 1e-10;
typedef long double Real;
// return -1, 0, 1
int sgn(const Real &r) { return (r > eps) - (r < -eps); }
int sgn(const Real &a, const Real &b) { return sgn(a - b); }

//.....................
const int MAX = (int)2e5 + 5;

vector<string> split(const string &str, char sep)
{
	vector<string> v;
	stringstream ss(str);
	string buffer;
	while (getline(ss, buffer, sep))
	{
		v.push_back(buffer);
	}
	return v;
}

template <class InputIterator>
int sum(InputIterator begin, InputIterator end)
{
	return accumulate(begin, end, 0ll);
}

template<typename T>
T gcd(T a, T b)
{
	T c;
	while (a != 0) {
		c = a; a = b%a;  b = c;
	}
	return b;
}

template<typename T>
T bit_count(T N) {
	T cnt = 0;
	while (N) {
		if (N & 1) cnt++;
		N >>= 1;
	}
	return cnt;
}

struct Point {
	int y, x;
	bool operator < (const Point& r) {
		if (x < r.x) return true;
		else return false;
	}
};

class Solver {
public:
	int K, N;
	vector<Point> points;
	vector<Point> selected;

	int dfs(int depth) {
		if (depth == 4) {
			assert(selected.size() == 4);
			int min_x = INF;
			int min_y = INF;
			int max_x = -INF;
			int max_y = -INF;
			rep(i, 4) {
				auto& p = selected[i];
				chmin(min_x, p.x);
				chmin(min_y, p.y);
				chmax(max_x, p.x);
				chmax(max_y, p.y);
			}
			if (min_x == max_x) max_x += 1;
			if (min_y == max_y) max_y += 1;
			int cnt = 0;
			rep(i, N) {
				auto& p = points[i];
				if (p.x >= min_x && p.y >= min_y
					&&p.x <= max_x && p.y <= max_y) cnt += 1;
			}
			if (cnt >= K) return (max_x - min_x) * (max_y - min_y);
			else return INF;
		}
		int res = INF;
		rep(i, N) {
			auto p = points[i];
			if (depth == 0);
			if (depth == 1) {
			}
			if (depth == 2) {
			}
			if (depth == 3) {
			}
			selected.push_back(p);
			int ret = dfs(depth + 1);
			selected.pop_back();
			chmin(res, ret);
		}
		return res;
	}

	void solve() {
		cin >> N >> K;
		points.resize(N);
		rep(i, N) {
			int x, y;
			cin >> x >> y;
			x--; y--;
			points[i].x = x;
			points[i].y = y;
		}
		cout << dfs(0) << endl;
	}
};

signed main()
{
	srand((unsigned int)time(NULL));
	cout << fixed << setprecision(20);
	auto ptr = new Solver();
	ptr->solve();
	delete ptr;
	//while (true) {
	//	if (cin.eof() == true) break;
	//	auto ptr = new Solver();
	//	ptr->solve();
	//	delete ptr;
	//}
	return 0;
}

Measured memory_bytes: 256