#include "bits/stdc++.h"
#define F first
#define S second
#define ll long long
#define pii pair<ll,ll>
const ll mxN = 3e5 + 5;
const ll mod = 1e9 + 7;
using namespace std;
struct node{
node *l,*r;
pii val;
node(): l(NULL), r(NULL), val({0,0}){}
};
node *root1 = new node(),*root2 = new node();
pii query(ll l,ll r,ll s,ll e,node *cur){
if(l > e || r < s) return {0,0};
if(l >= s && r <= e) return cur->val;
pii op1 = {0,0},op2 = {0,0};
ll md = (l + r) / 2;
if(cur->l) op1 = query(l,md,s,e,cur->l);
if(cur->r) op2 = query(md + 1,r,s,e,cur->r);
return max(op1,op2);
}
void update(ll l,ll r,ll ind,pii val,node *cur){
if(l == r){
cur->val = max(cur->val,val);
return;
}
ll md = (l + r) / 2;
if(!cur->l) cur->l = new node();
if(!cur->r) cur->r = new node();
if(ind <= md) {
update(l,md,ind,val,cur->l);
}
else {
update(md + 1,r,ind,val,cur->r);
}
cur->val = max(cur->l->val,cur->r->val);
}
struct player{
ll x,y,z;
friend bool operator<(player a, player b){
return tie(a.x,a.y,a.z) < tie(b.x,b.y,b.z);
}
};
struct upd{
ll ind;
pii val;
node *cur;
};
player a[mxN];
signed main(){
ll n;
cin >>n;
ll N;
for(ll i = 1;i <= n;i++){
cin >>a[i].x>> a[i].y>> a[i].z;
// N = max({a[i].x,a[i].y,a[i].z,N});
}
N = (1LL << 32);
sort(a + 1,a + n + 1);
ll ans = -1;
ll prev = 0;
queue<upd>buff;
for(ll i = 1;i <= n;i++){
// cout<<"TES\n";
if(a[i].x != prev){
while(buff.size()){
auto u = buff.front();
buff.pop();
update(1,N,u.ind,u.val,u.cur);
}
prev = a[i].x;
}
if(n <= 7000){
for(int j = 1;j < i;j++){
if(a[i].x == a[j].x || a[i].y >= a[j].y) continue;
pii x = query(1,N,1,a[j].y - 1,root1);
if(x.F > a[i].z && x.F > a[j].z) ans = max(ans,a[i].x + a[j].y + x.F);
}
buff.push({a[i].y,{a[i].z,a[i].y},root1});
}else{
pii x = query(1,N,1,a[i].y - 1,root1);
pii y = query(1,N,a[i].y + 1,N,root2);
pii z = query(1,N,1,a[i].y,root1);
cout<<"{ "<<x.F<<' '<<x.S<<" } , { "<<y.F<<' '<<y.S<<" }\n";
if(y.S && y.F - y.S > a[i].z) ans = max({ans,a[i].x + y.F});
// if(y.S && y.F - y.S > a[i].z && z.F > y.F - y.S && z.F > a[i].z) ans = max({ans,a[i].x + y.S + z.F});
if(x.S && x.F > a[i].z) buff.push({a[i].y,{x.F + a[i].y,a[i].y},root2});
update(1,N,a[i].y,{a[i].z,a[i].y},root1);
}
}
cout<<ans;
}
