This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
#define f1r(i, a, b) for (int i = a; i < b; ++i)
#define f0r(i, a) f1r(i, 0, a)
#define each(t, a) for (auto& t : a)
#define mp make_pair
#define f first
#define s second
#define pb push_back
#define eb emplace_back
#define sz(x) (int)(x).size()
#define all(x) begin(x), end(x)
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
template <class T> bool ckmin(T& a, const T& b) { return b < a ? a = b, 1 : 0; }
template <class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
const ll INF = 1e18;
int main() {
cin.tie(0)->sync_with_stdio(0);
int n; cin >> n;
vpi p(n);
f0r(i, n) cin >> p[i].f >> p[i].s;
auto run_dijkstra = [&](int beg) -> int {
typedef pair<ll, int> T;
priority_queue<T, vector<T>, greater<T>> pq;
vl dist(4 * n, INF);
vector<bool> vis(4 * n);
int cnt = 0;
auto ad = [&](int a, ll b) {
if (dist[a] <= b) return;
if (vis[a] && dist[a] == b) {
return;
}
vis[a] = true;
cnt++;
pq.push({dist[a] = b, a});
};
ad(beg, 0);
while (!pq.empty()) {
auto x = pq.top();
pq.pop();
int u = x.s / 4;
int d = x.s % 4;
if (dist[4 * u + d] < x.f) {
continue;
}
f0r(i, n) {
if (i == u) continue;
ll nd = 2 * max(abs(p[i].f - p[u].f), abs(p[i].s - p[u].s));
if (p[i].f == p[u].f) {
nd = abs(p[i].s - p[u].s);
} else if (p[i].s == p[u].s) {
nd = abs(p[i].f - p[u].f);
}
if (nd < x.f) continue;
if (p[i].f == p[u].f) {
if (p[i].s < p[u].s) {
if (d == 2) {
ad(4 * i + 0, nd);
}
} else {
if (d == 0) {
ad(4 * i + 2, nd);
}
}
} else if (p[i].s == p[u].s) {
if (p[i].f < p[u].f) {
if (d == 3) {
ad(4 * i + 1, nd);
}
} else {
if (d == 1) {
ad(4 * i + 3, nd);
}
}
} else if (p[i].f + p[i].s == p[u].f + p[u].s) {
if (p[i].f < p[u].f) {
if (d == 3) {
ad(4 * i + 2, nd);
} else if (d == 0) {
ad(4 * i + 1, nd);
}
} else {
if (d == 2) {
ad(4 * i + 3, nd);
} else if (d == 1) {
ad(4 * i + 0, nd);
}
}
} else if (p[i].f - p[i].s == p[u].f - p[u].s) {
if (p[i].f < p[u].f) {
if (d == 3) {
ad(4 * i + 0, nd);
} else if (d == 2) {
ad(4 * i + 1, nd);
}
} else {
if (d == 0) {
ad(4 * i + 3, nd);
} else if (d == 1) {
ad(4 * i + 2, nd);
}
}
}
}
}
int res = 0;
f0r(i, n) {
int a = 0;
f0r(d, 4) {
a += (dist[4 * i + d] < INF);
}
assert(a <= 1);
res += a;
}
assert(cnt <= n * 5);
return res;
};
int ans = 0;
f0r(d, 4) {
ckmax(ans, run_dijkstra(d));
}
cout << ans << '\n';
return 0;
}
/**
* first try n^2 bash
* 0 - up
* 1 - right
* 2 - down
* 3 - left
*/
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