#include<bits/stdc++.h>
using namespace std;
#define int long long
#define fi first
#define se second
#define pb push_back
signed main()
{
ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
// freopen("input.000","r",stdin);
// freopen("output.000","w",stdout);
// srand((unsigned)time(NULL));
// rand()
int n,i,cur_num,cur_id,cur_x,fur_x,cur_y,fur_y,j,ans;
static pair<int,pair<int,int>> a[150005];
queue<pair<int,int>> q;
cin>>n;
for (i=1;i<n+1;i++) cin>>a[i].se.fi>>a[i].se.se>>a[i].fi;
sort(a+1,a+n+1);
// for (i=1;i<n+1;i++) cout<<y[i].fi<<y[i].se.fi<<y[i].se.se<<"\n";
cur_x=cur_y=fur_x=fur_y=0;
cur_num=a[1].fi;
cur_id=1;
ans=-1;
for (i=1;i<n+1;i++)
{
if (cur_num < a[i].fi)
{
for (j=cur_id; j<i; j++)
if (a[j].se.fi >= fur_x and a[j].se.se >= fur_y)
{
fur_x=a[j].se.fi;
fur_y=a[j].se.se;
}
else
{
cur_x=fur_x=max(fur_x,a[j].se.fi);
cur_y=fur_y=max(fur_y,a[j].se.se);
}
cur_id=i;
cur_num=a[i].fi;
}
if (a[i].se.fi < cur_x and a[i].se.se < cur_y)
ans=max(ans,a[i].fi + cur_x + cur_y);
}
cout<<ans;
}
