#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 5;
array<int, 3> a[maxn];
vector<int> ys, zs;
struct FenwickTree{
int tree[maxn];
void update(int id, int val){
for(; id < maxn; id += id & (-id)) tree[id] = max(tree[id], val);
}
int get(int id){
int res = 0;
for(; id; id -= id & (-id)) res = max(res, tree[id]);
return res;
}
} bity, bitz;
void solve(){
int n; cin >> n;
for(int i = 1; i <= n; i++){
cin >> a[i][0] >> a[i][1] >> a[i][2];
ys.push_back(a[i][1]);
zs.push_back(a[i][2]);
}
sort(ys.begin(), ys.end());
sort(zs.begin(), zs.end());
ys.erase(unique(ys.begin(), ys.end()), ys.end());
zs.erase(unique(zs.begin(), zs.end()), zs.end());
for(int i = 1; i <= n; i++){
a[i][1] = lower_bound(ys.begin(), ys.end(), a[i][1]) - ys.begin() + 1;
a[i][2] = lower_bound(zs.begin(), zs.end(), a[i][2]) - zs.begin() + 1;
}
sort(a + 1, a + n + 1);
int res = 0, y = 0, z = 0, j = 1;
for(int i = 1; i <= n; i++){
if (a[i][0] != a[i - 1][0]){
for (int k = j; k < i; k++){
int tmpz = bity.get(a[k][1] - 1), tmpy = bitz.get(a[k][2] - 1);
//tmpz lớn nhất bé hơn a[k][1];
//tmpy lớn nhất bé hơn a[k][2];
//nếu tmpz lớn hơn a[k][2], và tmpz >= z và a[k][1] >= y;
if (tmpz > a[k][2] && tmpz + a[k][1] >= y + z){
y = a[k][1];
z = tmpz;
}
if (tmpy > a[k][1] && tmpy + a[k][2] >= y + z){
y = tmpy;
z = a[k][2];
}
bity.update(a[k][1], a[k][2]);
bitz.update(a[k][2], a[k][1]);
}
j = i;
}
if (y > a[i][1] && z > a[i][2]) res = max(res, a[i][0] + ys[y - 1] + zs[z - 1]);
}
cout << (res ? res : -1);
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
solve();
}
