#include <bits/stdc++.h> #define ll long long #define itachi ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0); #define maxn 2005 #define int long long using namespace std; const long double PI = acosl(-1.0L); const long double EPS = 1e-18L; int n; int X[maxn], Y[maxn], W[maxn]; struct Node { int sum, pre, suf, best; Node(int v = 0) { sum = v; pre = suf = best = max(0LL, v); } }; Node st[4 * maxn]; Node combine(const Node &L, const Node &R) { Node res; res.sum = L.sum + R.sum; res.pre = max(L.pre, L.sum + R.pre); res.suf = max(R.suf, R.sum + L.suf); res.best = max({L.best, R.best, L.suf + R.pre}); return res; } void build(int id, int l, int r, const vector<int> &arr) { if (l == r) { st[id] = Node(arr[l]); return; } int mid = (l + r) >> 1; build(id << 1, l, mid, arr); build(id << 1 | 1, mid + 1, r, arr); st[id] = combine(st[id << 1], st[id << 1 | 1]); } void update(int id, int l, int r, int pos, int val) { if (l == r) { st[id] = Node(val); return; } int mid = (l + r) >> 1; if (pos <= mid) update(id << 1, l, mid, pos, val); else update(id << 1 | 1, mid + 1, r, pos, val); st[id] = combine(st[id << 1], st[id << 1 | 1]); } struct Event { long double ang; int u, v; bool operator < (const Event &other) const { if (fabsl(ang - other.ang) > EPS) return ang < other.ang; if (u != other.u) return u < other.u; return v < other.v; } }; signed main() { itachi cin>>n; for (int i = 1; i <= n; i++) { cin >> X[i] >> Y[i] >> W[i]; } vector<Event> events; for (int i = 1; i <= n; i++) { for (int j = i + 1; j <= n; j++) { long double dx = X[j] - X[i]; long double dy = Y[j] - Y[i]; long double ang = atan2l(dy, dx); if (ang < 0) ang += PI; if (ang >= PI - EPS) ang -= PI; events.push_back({ang, i, j}); } } sort(events.begin(), events.end()); vector<int> ord(n + 1); for (int i = 1; i <= n; i++) ord[i] = i; sort(ord.begin() + 1, ord.end(), [&](int a, int b) { if (fabsl(Y[a] - Y[b]) > 1e-18) return Y[a] < Y[b]; return X[a] < X[b]; }); vector<int> pos(n + 1); vector<int> initial_w(n + 1); for (int i = 1; i <= n; i++) { pos[ord[i]] = i; initial_w[i] = W[ord[i]]; } build(1, 1, n, initial_w); int ans = st[1].best; for (int i = 0; i < (int)events.size(); ) { int j = i; while (j < (int)events.size() && fabsl(events[j].ang - events[i].ang) < EPS) { j++; } int L = n + 1, R = 0; for (int k = i; k < j; k++) { L = min({L, pos[events[k].u], pos[events[k].v]}); R = max({R, pos[events[k].u], pos[events[k].v]}); } reverse(ord.begin() + L, ord.begin() + R + 1); for (int k = L; k <= R; k++) { pos[ord[k]] = k; update(1, 1, n, k, W[ord[k]]); } ans = max(ans, st[1].best); i = j; } cout << ans << endl; return 0; }