#include <bits/stdc++.h>
using namespace std;
using namespace std::placeholders;
#define llong long long
#define xx first
#define yy second
#define len(x) ((int)x.size())
#define rep(i,n) for (int i = -1; ++ i < n; )
#define rep1(i,n) for (int i = 0; i ++ < n; )
#define all(x) x.begin(), x.end()
#define sgn(x) ((x) < 0 ? -1 : (x) > 0)
#define clog if (0) cerr
// #define rand __rand
// mt19937 rng(chrono::system_clock::now().time_since_epoch().count()); // or mt19937_64
// template<class T = int> T rand(T range = numeric_limits<T>::max()) {
// return (T)(rng() % range);
// }
struct itnode {
llong max_sum_subarr, max_left_sum, max_right_sum, sum;
itnode *lchild, *rchild;
int l, r; // [l; r)
itnode(int l_, int r_, function<llong(int)> getitem)
: lchild(0), rchild(0), l(l_), r(r_)
{
if (l + 1 == r) {
assign(getitem(l));
}
if (l + 1 >= r) return ;
int mid = (l + r) / 2;
lchild = new itnode(l, mid, getitem);
rchild = new itnode(mid, r, getitem);
merge();
}
~itnode() {
if (!lchild) return ;
delete lchild; delete rchild;
}
void assign(llong val) {
sum = val;
max_sum_subarr = sum;
max_right_sum = max_left_sum = max(sum, 0ll);
}
void merge() {
if (!lchild || !rchild) return ;
sum = lchild->sum + rchild->sum;
max_sum_subarr = max({lchild->max_sum_subarr, rchild->max_sum_subarr, lchild->max_right_sum + rchild->max_left_sum});
max_left_sum = max(lchild->max_left_sum, lchild->sum + rchild->max_left_sum);
max_right_sum = max(rchild->max_right_sum, rchild->sum + lchild->max_right_sum);
}
void inc(int pos, llong val) {
if (pos < l or pos >= r) return ;
if (l + 1 == r) {
assign(sum + val);
return ;
}
lchild->inc(pos, val);
rchild->inc(pos, val);
merge();
}
void dolog() {
if (!lchild) {
clog << setw(4) << sum << ' ';
} else {
lchild->dolog();
rchild->dolog();
}
}
};
struct line {
llong a, b, c; // ax + by + c = 0
line(llong a_ = 0, llong b_ = 0, llong c_ = 0) : a(a_), b(b_), c(c_) {}
line& norm() {
llong g = __gcd(a, b);
g = __gcd(g, c);
a /= g;
b /= g;
c /= g;
// the normal will point almost the same way as Oy
// also the line a == b == 0 does not "really" exist, no need to handle it.
if (b < 0 || (b == 0 and a < 0)) {
a = -a; b = -b; c = -c;
}
return *this;
}
template<class Point>
static line through_points(Point const& u, Point const& v) {
return line(
u.y - v.y,
- u.x + v.x,
u.x * v.y - u.y * v.x
).norm();
}
};
bool operator == (const line& lhs, const line& rhs) {
return lhs.a == rhs.a and lhs.b == rhs.b and lhs.c == rhs.c;
}
#define maxn 2020
struct spot {
llong x, y, cost;
int pos;
spot(llong x_ = 0, llong y_ = 0, llong v = 0) : x(x_), y(y_), cost(v), pos(0) {}
};
struct cmp_line {
bool operator()(const line& lhs, const line& rhs) const {
int cross = sgn(lhs.a * rhs.b - lhs.b * rhs.a);
if (cross == 0) return lhs.c < rhs.c;
return cross > 0;
}
};
int n;
spot a[maxn];
int main(void) {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n;
rep(i, n) cin >> a[i].x >> a[i].y >> a[i].cost;
sort(a, a + n, [](const spot& u, const spot& v) {
return (u.x == v.x) ? u.y > v.y : u.x < v.x;
});
rep(i, n) a[i].pos = i;
rep(i, n) {
clog << i << ":" << a[i].x << ' ' << a[i].y << ' ' << a[i].cost << endl;
}
map<line, vector<spot*>, cmp_line> group;
rep(i, n) {
for (int f = i + 1; f < n; ++f) {
line ln = line::through_points(a[i], a[f]);
group[ln].push_back(a + i);
group[ln].push_back(a + f);
}
}
itnode tree(0, n, [](int u) { return a[u].cost; });
llong ans = 0;
auto upd_ans = [&]() {
clog << setw(3) << ans << ' ' << setw(3) << tree.max_sum_subarr << ": ";
tree.dolog(); clog << endl;
ans = max(ans, tree.max_sum_subarr);
};
upd_ans();
vector<vector<spot*>> to_be_processed;
auto process = [&]() {
for (auto& i: to_be_processed) {
sort(i.begin(), i.end(), [](spot* u, spot* v) { return u->pos < v->pos; });
i.resize(unique(i.begin(), i.end()) - i.begin());
rep1(f, len(i) - 1) {
tree.inc(i[f]->pos, -i[f]->cost);
tree.inc(i[0]->pos, i[f]->cost);
}
}
upd_ans();
for (auto& i: to_be_processed) {
int first_pos = i[0]->pos;
rep(f, len(i) - 1) {
tree.inc(first_pos, -i[f]->cost);
if (f < len(i) - f - 1) swap(i[f]->pos, i[len(i) - f - 1]->pos);
tree.inc(i[f]->pos, i[f]->cost);
}
}
upd_ans();
};
line cur_line(1, 0, 0);
for (auto& [ln, points]: group) {
if (cur_line.a != ln.a or cur_line.b != ln.b) {
clog << "=== process" << endl;
process();
to_be_processed.clear();
cur_line = ln;
}
to_be_processed.push_back(move(points));
clog << "line : " << -ln.b << ' ' << ln.a << endl;
}
process();
cout << ans;
return 0;
}
