#include <algorithm>
#include <functional>
#include <iostream>
#include <iomanip>
#include <vector>
#include <map>
#include <set>
#include <unordered_set>
#include <queue>
#include <numeric>
#include <bitset>
#include <cmath>
#include <random>

using namespace std;
using ll = long long;
using ull = unsigned long long;
//const ll mod = 998244353;
const ll mod = 1000000007;
const int inf = 1e9;
const ll linf = 1e18;
const int dx[] = {1, -1, 0, 0};
const int dy[] = {0, 0, 1, -1};


#define REP(i, n) for (ll i = 0; i < (n); ++i)
#define REP_FROM(i, j, n) for (ll i = (j); i < (n); ++i)
#define REP_REV(i, n) for (ll i = n-1; i >= 0; --i)
#define REP_FROM_REV(i, j, n) for (ll i = n-1; i >= j; --i)
#define all(x) (x).begin(),(x).end()
#define sz(x) ll(x.size())

template<typename T>
inline T chmax(T &a, const T b) { return a = (a < b) ? b : a; }

template<typename T>
inline T chmin(T &a, const T b) { return a = (a > b) ? b : a; }

ll power(ll base, ll exponent) {
  if (exponent % 2) {
    return power(base, exponent - 1) * base % mod;
  } else if (exponent) {
    ll root_ans = power(base, exponent / 2);
    return root_ans * root_ans % mod;
  } else { return 1; }
}

ll inverse(ll x) { return power(x, mod - 2); }

ll gcd(ll a, ll b) {
  if (a < b) gcd(b, a);
  ll r;
  while (r = a % b) {
    a = b;
    b = r;
  }
  return b;
}

template<typename T>
ll sum(T begin, T end) { return accumulate(begin, end, 0ll); }

struct combination {
    vector<ll> fact, inv;

    combination(int sz) : fact(sz + 1), inv(sz + 1) {
      fact[0] = 1;
      for (int i = 1; i <= sz; i++) { fact[i] = fact[i - 1] * i % mod; }
      inv[sz] = power(fact[sz], mod - 2);
      for (int i = sz - 1; i >= 0; i--) { inv[i] = inv[i + 1] * (i + 1) % mod; }
    }

    ll C(int p, int q) const {
      if (q < 0 || p < q) return 0;
      return (fact[p] * inv[q] % mod * inv[p - q] % mod);
    }
};

using Pair = pair<int, int>;
using LPair = pair<ll, ll>;

template<ll Modulus>
struct ModInt {
    ll a;

    constexpr ModInt(const ll x = 0) noexcept: a((x % mod + mod) % mod) {}

    constexpr ll &value() noexcept { return a; }

    constexpr const ll &value() const noexcept { return a; }

    constexpr ModInt operator+(const ModInt x) const noexcept {
      return ModInt(*this) += x;
    }

    constexpr ModInt operator-(const ModInt x) const noexcept {
      return ModInt(*this) -= x;
    }

    constexpr ModInt operator*(const ModInt x) const noexcept {
      return ModInt(*this) *= x;
    }

    constexpr ModInt operator/(const ModInt x) const noexcept {
      return ModInt(*this) /= x;
    }

    constexpr ModInt &operator+=(const ModInt x) noexcept {
      a += x.a;
      if (a >= Modulus) {
        a -= Modulus;
      }
      return *this;
    }

    constexpr ModInt &operator-=(const ModInt x) noexcept {
      if (a < x.a) {
        a += Modulus;
      }
      a -= x.a;
      return *this;
    }

    constexpr ModInt &operator*=(const ModInt x) noexcept {
      a = a * x.a % Modulus;
      return *this;
    }

    constexpr ModInt &operator/=(ModInt x) noexcept {
      ll exp = Modulus - 2;
      while (exp) {
        if (exp % 2) {
          *this *= x;
        }
        x *= x;
        exp /= 2;
      }
      return *this;
    }

    constexpr ModInt operator-() noexcept {
      return ModInt(-a);
    }

    friend ostream &operator<<(ostream &os, const ModInt &m) {
      os << m.a;
      return os;
    }
};

using mint = ModInt<mod>;

map<ll, ll> compress(const vector<ll> &a) {
  vector<ll> b = a;
  sort(all(b));
  b.erase(unique(all(b)), b.end());
  map<ll, ll> mp;
  REP(i, sz(b)) {
    mp[b[i]] = i;
  }
  return mp;
}

signed main() {
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(15);
  ll n, K;
  cin >> n >> K;
  vector<ll> x(n), y(n);
  REP(i, n) cin >> x[i] >> y[i];
  map<ll, ll> mpx = compress(x);
  map<ll, ll> mpy = compress(y);
  ll ch = 0, cw = 0;
  REP(i, n) {
    chmax(ch, mpy[y[i]] + 1);
    chmax(cw, mpx[x[i]] + 1);
  }
  vector<vector<ll>> cum(ch + 1, vector<ll>(cw + 1));
  map<Pair, int> mp;
  REP(i, n) {
    mp[{mpy[y[i]], mpx[x[i]]}]++;
  }
  if(K==1) {
    cout << 1 << endl;
    return 0;
  }
  if(K==2) {
    ll ans = 5 * linf;
    REP(i, n) {
      REP_FROM(j, i + 1, n) {
        ll s = max(max(y[i], y[j]) - min(y[i], y[j]), 1ll) * max(max(x[i], x[j]) - min(x[i], x[j]), 1ll);
        chmin(ans, s);
      }
    }
    cout << ans << endl;
    return 0;
  }
  if(K==3) {
    ll ans = 5 * linf;
    REP(i, n) {
      REP_FROM(j, i+1, n) {
        REP_FROM(k, j+1, n) {
          ll ly = min({y[i], y[j], y[k]});
          ll lx = min({x[i], x[j], x[k]});
          ll ry = max({y[i], y[j], y[k]});
          ll rx = max({x[i], x[j], x[k]});
          ll s = max(ry - ly, 1ll) * max(rx - lx, 1ll);
          chmin(ans, s);
        }
      }
    }
    cout << ans << endl;
    return 0;
  }
  REP(i, ch) {
    REP(j, cw) {
      cum[i+1][j+1] = cum[i+1][j] + cum[i][j+1] - cum[i][j] + mp[{i, j}];
    }
  }
  ll ans = linf * 5;
  REP(i, n) {
    REP_FROM(j,  i+1, n) {
      REP_FROM(k, j+1, n) {
        REP_FROM(l, k+1, n) {
          ll ly = min({y[i], y[j], y[k], y[l]});
          ll lx = min({x[i], x[j], x[k], x[l]});
          ll ry = max({y[i], y[j], y[k], y[l]});
          ll rx = max({x[i], x[j], x[k], x[l]});
          ll cnt = cum[mpy[ry]+1][mpx[rx]+1] + cum[mpy[ly]][mpx[lx]] - cum[mpy[ry]+1][mpx[lx]] - cum[mpy[ly]][mpx[rx]+1];
          ll s = max(ry - ly, 1ll) * max(rx - lx, 1ll);
          if(cnt >= K) chmin(ans, s);
        }
      }
    }
  }
  cout << ans << endl;
}

Measured memory_bytes: 3856