# include <iostream>
# include <vector>
# include <algorithm>
# include <set>
using namespace std;
const int MAX=2e5+11;
int n,q;
struct point
{
int x,y,z;
}a[MAX];
bool cmpX(point A, point B)
{
return A.x<B.x;
}
bool cmpY(point A, point B)
{
return A.y<B.y;
}
bool cmpZ(point A, point B)
{
return A.z<B.z;
}
int nY,nZ;
int realY[MAX];
int realZ[MAX];
struct segtree
{
int N;
int tree[MAX*4];
void build(int v, int l, int r)
{
if(l==r)
{
tree[v]=0;
return ;
}
int mid=(l+r)/2;
build(v*2,l,mid);
build(v*2+1,mid+1,r);
tree[v]=max(tree[v*2],tree[v*2+1]);
}
void init(int _N)
{
N=_N;
build(1,1,N);
}
void update(int pos, int d, int v, int l, int r)
{
if(l==r)
{
tree[v]=max(tree[v],d);
return ;
}
int mid=(l+r)/2;
if(pos<=mid) update(pos,d,v*2,l,mid);
else update(pos,d,v*2+1,mid+1,r);
tree[v]=max(tree[v*2],tree[v*2+1]);
}
void update(int pos, int d)
{
update(pos,d,1,1,N);
}
int query(int le, int ri, int v, int l, int r)
{
if(ri<l or r<le) return 0;
if(le<=l and r<=ri) return tree[v];
int mid=(l+r)/2;
return max(query(le,ri,v*2,l,mid),query(le,ri,v*2+1,mid+1,r));
}
int query(int le, int ri)
{
return query(le,ri,1,1,N);
}
}treeY,treeZ;
vector<pair<int,int>> bst;
void add(pair<int,int> pa)
{
bst.push_back(pa);
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin>>n;
for(int i=1;i<=n;i++) cin>>a[i].x>>a[i].y>>a[i].z;
sort(a+1,a+n+1,cmpX);
vector<pair<int,int>> temp;
for(int i=1;i<=n;i++) temp.push_back({a[i].y,i});
sort(temp.begin(),temp.end());
int last=-1;
for(pair<int,int> pa: temp)
{
if(pa.first!=last)
{
last=pa.first;
nY++;
realY[nY]=last;
}
a[pa.second].y=nY;
}
temp.clear();
for(int i=1;i<=n;i++) temp.push_back({a[i].z,i});
sort(temp.begin(),temp.end());
last=-1;
for(pair<int,int> pa: temp)
{
if(pa.first!=last)
{
last=pa.first;
nZ++;
realZ[nZ]=last;
}
a[pa.second].z=nZ;
}
treeY.init(nY);
treeZ.init(nZ);
int ptr=1,ans=-1;
for(int i=1;i<=n;i++)
{
while(a[ptr].x<a[i].x)
{
if(a[ptr].y!=1) add({a[ptr].y,treeY.query(1,a[ptr].y-1)});
if(a[ptr].z!=1) add({treeZ.query(1,a[ptr].z-1),a[ptr].z});
treeY.update(a[ptr].y,a[ptr].z);
treeZ.update(a[ptr].z,a[ptr].y);
ptr++;
}
for(pair<int,int> pa: bst)
{
if(pa.first>a[i].y and pa.second>a[i].z) ans=max(ans,a[i].x+realY[pa.first]+realZ[pa.second]);
}
}
cout<<ans<<"\n";
return 0;
}
