#include <bits/stdc++.h>
#define endl "\n"
#define mod 1000000007
using namespace std;
#define int long long
const int N=(1<<19);
int Tree[N*2+5][2];
int n,inf=3e10;
array <int,6> arr[150001],Marr[150001];
int cnt=0;
void update(int i,int val,int u){
i+=N;
Tree[i][u]=max(Tree[i][u],val);
i/=2;
while(i!=0){
Tree[i][u]=max(Tree[i*2][u],Tree[i*2+1][u]);
i/=2;
}
return;
}
int solve(int l1,int r1,int i,int l,int r,int u){
if(l1>r||l>r1) return -inf;
if(l<=l1&&r1<=r) return Tree[i][u];
return max(solve(l1,(l1+r1)/2,i*2,l,r,u),solve((l1+r1)/2+1,r1,i*2+1,l,r,u));
}
void compress(){
set <int> comp;
map <int,int> key;
for(int i=1;i<=n;i++){
comp.insert(arr[i][0]);
comp.insert(arr[i][1]);
comp.insert(arr[i][2]);
}
for(int i:comp){
key[i]=++cnt;
}
for(int i=1;i<=n;i++) for(int u=0;u<=2;u++) arr[i][u]=key[arr[i][u]];
return;
}
int calc(){
for(int i=0;i<=N*2+4;i++) Tree[i][0]=Tree[i][1]=-inf;
for(int i=1;i<=n;i++) arr[i]=Marr[i];
compress();
sort(arr+1,arr+n+1);
// for(int i=1;i<=n;i++) cout<<arr[i][0]<<" "<<arr[i][1]<<" "<<arr[i][2]<<endl;
// exit(0);
int mx=-1;
for(int i=1;i<=n;i++){
for(int j=i+1;j<=n;j++){
if(arr[i][1]<=arr[j][1]) continue;
int val=solve(0,N-1,1,0,arr[i][1]-1,0);
if(val<=max(arr[i][5],arr[j][5])) continue;
mx=max(mx,arr[j][3]+arr[i][4]+val);
}
for(int j=i+1;j<=n;j++){
if(arr[i][2]<=arr[j][2]) continue;
int val=solve(0,N-1,1,0,arr[i][2]-1,1);
if(val<=max(arr[i][4],arr[j][4])) continue;
mx=max(mx,arr[j][3]+arr[i][5]+val);
}
update(arr[i][1],arr[i][5],0);
update(arr[i][2],arr[i][4],1);
}
return mx;
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin>>n;
for(int i=1;i<=n;i++){
cin>>Marr[i][0]>>Marr[i][1]>>Marr[i][2];
Marr[i][3]=Marr[i][0];
Marr[i][4]=Marr[i][1];
Marr[i][5]=Marr[i][2];
}
cout<<calc()<<endl;
}
