#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;
int n;
struct info{
int x, y, z;
info(): x(0), y(0), z(0) {}
info(int x, int y, int z): x(x), y(y), z(z) {}
} a[N];
int lim, pre_y[N], pre_z[N];
vector<int> rrh;
void init(){
for(int i = 1; i <= n; i++){
rrh.push_back(a[i].y);
rrh.push_back(a[i].z);
}
sort(rrh.begin(), rrh.end());
rrh.erase(unique(rrh.begin(), rrh.end()), rrh.end());
for(int i = 1; i <= n; i++){
a[i].y = lower_bound(rrh.begin(), rrh.end(), a[i].y) - rrh.begin() + 1;
a[i].z = lower_bound(rrh.begin(), rrh.end(), a[i].z) - rrh.begin() + 1;
}
lim = rrh.size();
}
struct BIT2D{
vector<int> node[N], bit[N];
void fake_update(int x, int y){
for(int i = x; i > 0; i -= i & -i) node[i].push_back(y);
}
void fake_get(int x, int y){
for(int i = x; i <= lim; i += i & -i) node[i].push_back(y);
}
void init(){
for(int i = 1; i <= lim; i++){
auto &a = node[i];
sort(a.begin(), a.end());
a.erase(unique(a.begin(), a.end()), a.end());
bit[i].resize(a.size(), -1);
}
}
void update(int x, int y, int val){
for(int i = x; i > 0; i -= i & -i)
for(int j = lower_bound(node[i].begin(), node[i].end(), y) - node[i].begin() + 1; j > 0; j -= j & -j){
bit[i][j - 1] = max(bit[i][j - 1], val);
}
}
int get(int x, int y){
int res = -1;
for(int i = x; i <= lim; i += i & -i)
for(int j = lower_bound(node[i].begin(), node[i].end(), y) - node[i].begin() + 1; j <= node[i].size(); j += j & -j){
res = max(res, bit[i][j - 1]);
}
return res;
}
} fwk2d;
struct BIT{
int bit[N];
void build(){
memset(bit, -1, sizeof bit);
}
void update(int i, int x){
for(; i <= lim; i += i & -i) bit[i] = max(bit[i], x);
}
int get(int i){
int res = -1;
for(; i > 0; i -= i & -i) res = max(res, bit[i]);
return res;
}
} fwk1, fwk2;
void fakeSolve(){
int ptl = 1;
fwk1.build();
fwk2.build();
for(int i = 1; i <= n; i++){
fwk2d.fake_get(a[i].y, a[i].z);
if(i < n && a[i].x < a[i + 1].x){
while(ptl <= i){
int _z = fwk1.get(a[ptl].y - 1); pre_z[ptl] = _z;
int _y = fwk2.get(a[ptl].z - 1); pre_y[ptl] = _y;
if(_z != -1 && _z > a[ptl].z) fwk2d.fake_update(a[ptl].y, _z);
if(_y != -1 && _y > a[ptl].z) fwk2d.fake_update(_y, a[ptl].z);
fwk1.update(a[ptl].y, a[ptl].z);
fwk2.update(a[ptl].z, a[ptl].y);
ptl += 1;
}
}
}
fwk2d.init();
}
void Solve(){
int ptl = 1, res = -1;
for(int i = 1; i <= n; i++){
int tmp = fwk2d.get(a[i].y, a[i].z);
if(tmp != -1) res = max(res, a[i].x + tmp);
if(i < n && a[i].x < a[i + 1].x){
while(ptl <= i){
int _z = pre_z[ptl];
int _y = pre_y[ptl];
if(_z != -1 && _z > a[ptl].z) fwk2d.update(a[ptl].y, _z, rrh[a[ptl].y - 1] + rrh[_z - 1]);
if(_y != -1 && _y > a[ptl].z) fwk2d.update(_y, a[ptl].z, rrh[_y - 1] + rrh[a[ptl].z - 1]);
ptl += 1;
}
}
}
cout << res << "\n";
}
int32_t main(){
cin.tie(0)->sync_with_stdio(0);
// #define task "test"
// if(fopen(task ".inp", "r")){
// freopen(task ".inp", "r", stdin);
// freopen(task ".out", "w", stdout);
// }
cin >> n;
for(int i = 1; i <= n; i++){
int x, y, z; cin >> x >> y >> z;
a[i] = {x, y, z};
}
sort(a + 1, a + n + 1, [&](info a, info b){ return a.x < b.x; });
init();
fakeSolve();
Solve();
}
