#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

int dist[510][510];

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, k;
  cin >> n >> k;
  n += 2;
  vector<P> xy(n);
  for(auto& [x, y] : xy) cin >> x >> y;
  rep(i, n) rep(j, n) {
    auto [xi, yi] = xy[i];
    auto [xj, yj] = xy[j];
    dist[i][j] = abs(xi - xj) + abs(yi - yj);
  }
  int l = 0, r = dist[0][1];
  constexpr int INF = 1001001001;
  while(r - l > 1) {
    int c = (l + r) / 2;
    VI cost(n, INF);
    cost[0] = 0;
    VI unvisited;
    rep(i, n) if (i) {
      cost[i] = (dist[0][i] - 1) / c;
      unvisited.emplace_back(i);
    }
    while(unvisited.size()) {
      int u = -1, cu = INF;
      for(int x: unvisited) if (chmin(cu, cost[x])) u = x;
      assert(u != -1);
      unvisited.erase(find(all(unvisited), u));
      for(int v : unvisited) chmin(cost[v], cost[u] + (dist[u][v] - 1) / c);
    }
    (cost[1] <= k ? r : l) = c;
  }
  cout << r << '\n';
}