#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
namespace x = __gnu_pbds;
template <typename T, typename Comp = less<T>>
using ordered_set = x::tree<T, x::null_type, Comp, x::rb_tree_tag, x::tree_order_statistics_node_update>;
template <typename T>
using normal_queue = priority_queue<T, vector<T>, greater<>>;
#define all(x) begin(x), end(x)
#define sz(x) ((int) (x).size())
#define x first
#define y second
using ll = long long;
using ld = long double;
const int N = 1.6e5;
using P = array<int, 3>;
P a[N];
signed main() {
cin.tie(0)->sync_with_stdio(0);
int n;
cin >> n;
for (int i = 0; i < n; ++i) {
for (int j = 0; j < 3; ++j) {
cin >> a[i][j];
}
}
sort(a, a + n);
ordered_set<pair<int, int>, greater<>> f, b;
f.insert({a[0][1], a[0][2]}), b.insert({a[0][2], a[0][1]});
ll ans = -1;
int y = -1, z = -1;
vector<tuple<int, int, int>> cands;
for (int i = 1; i < n - 1; ++i) {
// add a[i]
auto [fit, sc1] = f.insert({a[i][1], a[i][2]});
auto [bit, sc2] = b.insert({a[i][2], a[i][1]});
if (sc1) {
assert(sc2);
{
int j = int(f.order_of_key({a[i][1], a[i][2]}));
auto other = *b.find_by_order(j);
if (pair{a[i][2], a[i][1]} != other) {
y = max({y, a[i][1], other.y});
z = max({z, a[i][2], other.x});
}
}
{
int j = int(b.order_of_key({a[i][2], a[i][1]}));
auto other = *f.find_by_order(j);
if (pair{a[i][1], a[i][2]} != other) {
y = max({y, a[i][1], other.x});
z = max({z, a[i][2], other.y});
}
}
}
if (a[i][0] == a[i + 1][0]) {
continue;
}
// [0; i] and [i + 1; n - 1]
int x = -1;
for (int j = i + 1; j <= i + 1; ++j) {
if (a[j][1] < y && a[j][2] < z) {
x = a[j][0];
break;
}
}
if (x != -1) {
ans = max(ans, 0ll + x + y + z);
}
}
cout << ans;
}
