#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
#define fi first
#define se second
#define vi vector<int>
#define vll vector<long long>
#define pii pair<int, int>
#define pll pair<long long, long long>
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::high_resolution_clock::now().time_since_epoch().count());
inline int rand(int l,int r){return uniform_int_distribution<int>(l, r)(rng);}
inline ll rand(ll l,ll r){return uniform_int_distribution<ll>(l, r)(rng64);}
#ifdef DEBUG
auto&operator<<(auto&o,pair<auto,auto>p){return o<<"("<<p.first<<", "<<p.second<<")";}
auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<","+!i++<<e;return o<<"}";}
#define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(X)
#else
#define debug(...){}
#endif
struct custom_hash {
static uint64_t splitmix64(uint64_t x) {
x += 0x9e3779b97f4a7c15;
x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
return x ^ (x >> 31);
}
size_t operator()(uint64_t x) const {
static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
return splitmix64(x + FIXED_RANDOM);
}
};
struct pair_hash{
size_t operator()(const pair<int,int>&x)const{
return hash<long long>()(((long long)x.first)^(((long long)x.second)<<32));
}
};
const int INF = 1e9;
const int MAXN = 150000 + 7;
const int BASE = (1 << 17);
int id[MAXN];
pair<pii, pii> A[MAXN];
int tree[2 * BASE + 7];
int mxY[2 * BASE + 7];
int n;
int queryMx(int v, int l, int p, int a, int b){
if(p < a || b < l){
return 0;
}
if(a <= l && p <= b){
return tree[v];
}
int mid = (l + p) / 2;
return max(queryMx(2 * v, l, mid, a, b), queryMx(2 * v + 1, mid + 1, p, a, b));
}
void upd(int ind, int val){
int i = ind;
ind += BASE;
while(ind){
tree[ind] = max(tree[ind], val);
mxY[ind] = max(mxY[ind], A[i].fi.se);
ind /= 2;
}
}
int findY(int v, int l, int p, int a, int b, int z){
if(p < a || b < l || tree[v] == 0){
return 0;
}
if(a <= l && p <= b){
if(l == p){
if(tree[v] < z){
return A[v - BASE].fi.se;
}
return 0;
}else{
if(tree[v] < z){
return mxY[v];
}
int mid = (l + p) / 2;
return max(findY(2 * v, l, mid, a, b, z), findY(2 * v + 1, mid + 1, p, a, b, z));
}
}
int mid = (l + p) / 2;
return max(findY(2 * v, l, mid, a, b, z), findY(2 * v + 1, mid + 1, p, a, b, z));
}
bool comp(pair<pii, pii> x, pair<pii, pii> y){
if(x.fi.se != y.fi.se){
return x.fi.se < y.fi.se;
}
return x.se.fi < y.se.fi;
}
int solve(){
for(int i = 1; i < 2 * BASE + 7; i++){
tree[i] = mxY[i] = 0;
}
sort(A, A + n, comp);
for(int i = 0; i < n; i++){
id[A[i].se.se] = i;
}
sort(A, A + n);
int res = -1;
for(int i = 0; i < n; i++){
int z = queryMx(1, 0, BASE - 1, 0, id[A[i].se.se] - 1);
if(z > A[i].se.fi){
int y = findY(1, 0, BASE - 1, id[A[i].se.se] + 1, n - 1, z);
if(y){
res = max(res, z + y + A[i].fi.fi);
}
}
upd(id[A[i].se.se], A[i].se.fi);
}
return res;
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
cin >> n;
for(int i = 0; i < n; i++){
cin >> A[i].fi.fi >> A[i].fi.se >> A[i].se.fi;
A[i].se.se = i;
}
int ans = solve();
for(int i = 0; i < n; i++){
swap(A[i].fi.fi, A[i].se.fi);
}
ans = max(ans, solve());
cout << ans << '\n';
return 0;
}
