#include<bits/stdc++.h>
using namespace std;
const long long value=1e18;
struct grp{
long long x,y,z;
} p[2*100010];
struct node{
long long mn=value,mx=-value;
} st[8*100010];
long long i,n,j=0,ans=-1,pos=1,N;
vector<long long> vec;
bool flag=0;
node merge_node(const node& A,const node& B){
if (A.mx<0) return B;
if (B.mx<0) return A;
return {min(A.mn,B.mn),max(A.mx,B.mx)};
}
void update(long long id,long long l,long long r,long long u,long long x){
if (r<u||u<l) return;
if (l>=r){
st[id].mn=min(st[id].mn,x);
st[id].mx=max(st[id].mx,x);
return;
}
long long mid=(l+r)/2;
update(2*id,l,mid,u,x);
update(2*id+1,mid+1,r,u,x);
st[id]=merge_node(st[2*id],st[2*id+1]);
}
node get(long long id,long long l,long long r,long long u,long long v){
if (u>v) return {value,-value};
if (r<u||v<l) return {value,-value};
if (u<=l&&r<=v) return st[id];
long long mid=(l+r)/2;
return merge_node(get(2*id,l,mid,u,v),get(2*id+1,mid+1,r,u,v));
}
long long bs(long long x){
for (long long i=N;i>=x;i--){
if (get(1,1,N,1,i-1).mx>get(1,1,N,i,N).mn) return i;
}
return -1;
}
signed main(){
//freopen("team.inp","r",stdin);
//freopen("team.out","w",stdout);
cin.tie(0)->sync_with_stdio(0);
cin>>n;
for (i=1;i<=n;i++) cin>>p[i].x>>p[i].y>>p[i].z;
sort(p+1,p+n+1,[](const grp& A,const grp& B){
return A.x<B.x;
});
long long j=0;
for (i=1;i<=n;i++){
vec.push_back(p[i].y);
}
sort(vec.begin(),vec.end());
vec.erase(unique(vec.begin(),vec.end()),vec.end());
for (i=1;i<=n;i++){
p[i].y=lower_bound(vec.begin(),vec.end(),p[i].y)-vec.begin()+1;
}
N=vec.size();
pos=1;
for (i=1;i<=n;i++){
//cout<<p[i].x<<" "<<p[i].y<<" "<<p[i].z<<"\n";
if (p[i].x!=p[i-1].x){
while (j+1<i){
j++;
update(1,1,N,p[j].y,p[j].z);
}
}
long long ca=bs(p[i].y+1);
if (ca<0) continue;
long long x=get(1,1,N,1,ca-1).mx;
if (p[i].z<x) ans=max(ans,p[i].x+vec[ca-1]+x);
}
cout<<ans;
}
