#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define sz(a) a.size()
#define all(a) a.begin(),a.end()
#define owo ios_base::sync_with_stdio(0);cin.tie(0);
typedef pair<int,int> pii;
typedef long long int ll;
const int MAXN = 5e5;
array<ll,3>pts[MAXN];
int bmx[MAXN];
//i have rectangle queries but i cant do it offline?
//i can but its double log on 2s
//ok try n^2 first
int main()
{
owo
int n;
cin>>n;
vector<array<ll,3>>a(n);
for(int i=0;i<n;i++){
for(int j=0;j<3;j++){
cin>>a[i][j];
}
}
sort(all(a),[&](array<ll,3>i,array<ll,3>j){return j[0] > i[0];});
//cout<<"sorted"<<'\n';
//for(int i=0;i<n;i++)cout<<a[i][0]<<" "<<a[i][1]<<" "<<a[i][2]<<'\n';
ll ans = -1;
for(int i=0;i<n;){
int k = i;
while(k+1<n && a[k][0] == a[k+1][0])k++;
for(int x=i;x<=k;x++){
for(int j=0;j<x;j++){
if(a[x][0] == a[j][0])break;
if(pts[j][2] <0)continue;
if(pts[j][1] > a[x][1] && pts[j][2] >a[x][2]){
ans = max(ans,a[x][0] + pts[j][0]);
}
}
}
for(int x=i;x<=k;x++){
pts[x][0] = -2e9;
pts[x][1] = a[x][1];
for(int j=0;j<x;j++){
if(a[j][1] > a[x][1] && a[j][2] < a[x][2]){
pts[j][2] = max(pts[j][2],a[x][2]);
pts[j][0] = pts[j][1] + pts[j][2];
}
if(a[j][1] < a[x][1] && a[j][2] > a[x][2]){
pts[x][2] = max(pts[x][2],a[j][2]);
pts[x][0] = pts[x][1] + pts[x][2];
}
}
}
i = k+1;
}
cout<<ans;
}
