#include <bits/stdc++.h>
using namespace std;
using ll = long long;
void print(array<int,3> v) {
cout << v[0] << ' ' << v[1] << ' ' << v[2] << '\n';
}
void clean(vector<array<int, 3>> & v) {
vector<array<int, 3>> res;
int n = v.size();
vector<int> yes(n, 1);
for (int t = 0; t < 3; ++t) {
map<vector<int>, vector<int>> f;
for (int i = 0; i < n; ++i) {
vector<int> x, y;
for (int j = 0; j < 3; ++j) {
if (j == t) y.push_back(v[i][j]);
else x.push_back(v[i][j]);
}
f[x].push_back(y[0]);
}
for (auto & [x, y]: f) sort(y.begin(), y.end());
for (int i = 0; i < n; ++i) {
vector<int> x;
for (int j = 0; j < 3; ++j) {
if (j != t) x.push_back(v[i][j]);
}
if (v[i][t] != f[x][0] && v[i][t] != f[x].back()) {
yes[i] = 0;
}
}
}
for (int i = 0; i < n; ++i) {
if (yes[i]) {
res.push_back(v[i]);
// cout << v[i][0] << ' ' << v[i][1] << ' ' << v[i][2] << '\n';
}
}
v = res;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
map<int, vector<pair<int, int>>> f;
set<array<int, 3>> seen;
vector<array<int, 3>> v;
for (int i = 0; i < n; ++i) {
int x, y, z;
cin >> x >> y >> z;
// if (seen.find({x, y, z}) != seen.end()) continue;
// seen.insert({x, y, z});
v.push_back({x, y, z});
}
// clean(v);
// n = v.size();
// for (int i = 0; i < n; ++i) {
// for (int j = i + 1; j < n; ++j) {
// for (int k = j + 1; k < n; ++k) {
// vector<int> z{0, 1, 2};
// do {
// if (v[i][z[0]] > max(v[j][z[0]], v[k][z[0]])) {
// if (v[j][z[1]] > max(v[i][z[1]], v[k][z[1]])) {
// if (v[k][z[2]] > max(v[i][z[2]], v[j][z[2]])) {
// // print(v[i]);
// // print(v[j]);
// // print(v[k]);
// // cout << (v[i][z[0]] + v[j][z[1]] + v[k][z[2]]) << '\n';
// }
// }
// }
// } while (next_permutation(z.begin(), z.end()));
// }
// }
// }
for (auto [x, y, z]: v) {
f[x].push_back({y, z});
}
set<pair<int, int>> st, ts;
int sx = -1, sy = -1;
int ans = -1;
for (auto & [d1, v]: f) {
// cout << "!!! " << d1 << " PRE " << sx << ' ' << sy << '\n';
// for (auto [x, y]: st) {
// // cout << x << ' ' << y << '\n';
// assert(ts.find({y, x}) != ts.end());
// }
// cout << "END\n";
for (auto [x, y]: v) {
if (x < sx && y < sy) {
ans = max(ans, d1 + sx + sy);
}
}
for (auto [x, y]: v) {
// cout << x << ' ' << y << '\n';
if (x <= sx && y <= sy) continue;
if (st.find({x, y}) != st.end()) continue;
auto it = st.upper_bound({x, y});
if (it != st.begin()) {
it--;
if ((*it).second > y) {
sx = x;
sy = (*it).second;
}
}
auto ti = ts.upper_bound({y, x});
if (ti != ts.begin()) {
ti--;
if ((*ti).second > x) {
sy = y;
sx = (*ti).second;
}
}
st.insert({x, y});
ts.insert({y, x});
while (st.size()) {
auto [x, y] = *st.begin();
if (x <= sx && y <= sy) {
st.erase(st.begin());
} else {
break;
}
}
while (ts.size()) {
auto [y, x] = *ts.begin();
if (x <= sx && y <= sy) {
ts.erase(ts.begin());
} else {
break;
}
}
}
}
cout << ans << "\n";
return 0;
}
