#include<bits/stdc++.h>

using i64 = int64_t;
struct frac_t {
	i64 num, den;
	frac_t() : num(0), den(1) {}
	frac_t(i64 n, i64 d) : num(n), den(d) {
		assert(den);
		if (den < 0) {
			num *= -1;
			den *= -1;
		}
		assert(den > 0);
	}
	friend bool operator<(const frac_t &a, const frac_t& b) {
		return a.num * b.den < b.num * a.den;
	}
};
int main() {
	using namespace std;
	using i64 = int64_t;
	cin.tie(nullptr)->sync_with_stdio(false);
	int N; cin >> N;

	vector<i64> S(N), E(N), Y(N), V;
	for (int i = 0; i < N; ++i) {
		cin >> S[i] >> E[i] >> Y[i];
		if (S[i] > E[i]) swap(S[i], E[i]);
		V.push_back(E[i] - S[i]);
	}

	i64 ans = 0;

	for (int i = 0; i < N; ++i) ans = max(ans, V[i]);

	for (int z = 0; z < N; ++z) {
		for (int steps = 0; steps < 2; ++steps) {
			i64 x = 0, y = 0, v = 0;
			if (steps & 1) {
				x = S[z], y = Y[z], v = V[z];
			}
			else {
				x = E[z], y = Y[z], v = V[z];
			}

			vector<pair<frac_t, i64>> pts;
			for (int i = 0; i < N; ++i) {
				if (y == Y[i]) continue;
				frac_t lo(S[i] - x, Y[i] - y);
				frac_t hi(E[i] - x, Y[i] - y);
				pts.emplace_back(lo, -V[i]);
				pts.emplace_back(hi, V[i]);
			}

			sort(pts.rbegin(), pts.rend());
			
			ans = max(ans, v);
			for (auto p : pts) {
				v += p.second;
				ans = max(ans, v);
			}
		}
	}

	cout << ans << '\n';
}