#include<bits/stdc++.h>
using namespace std;
int n;
vector<int> v[150005];
vector< pair<int,int> > a[3];
int seg1[600005], seg2[600005];
int mp[3][150005];
void seg1_upd(int x, int l, int r, int ll, int rr, int val) {
if(ll <= l && r <= rr) {
seg1[x] = max(seg1[x], val);
} else if(ll > r || rr < l) {
return;
} else {
seg1_upd(x*2, l, (l+r)/2, ll, rr, val);
seg1_upd(x*2+1, (l+r)/2+1, r, ll, rr, val);
}
}
void seg2_upd(int x, int l, int r, int ll, int rr, int val) {
if(seg2[x] == 0) seg2[x] = 1e9;
if(ll <= l && r <= rr) {
seg2[x] = min(seg2[x], val);
} else if(ll > r || rr < l) {
return;
} else {
seg2_upd(x*2, l, (l+r)/2, ll, rr, val);
seg2_upd(x*2+1, (l+r)/2+1, r, ll, rr, val);
}
}
int seg1_qry(int x, int l, int r, int pos) {
int tmp = seg1[x];
if(l != r) {
if(pos <= (l+r)/2) tmp = max(tmp, seg1_qry(x*2, l, (l+r)/2, pos));
else tmp = max(tmp, seg1_qry(x*2+1, (l+r)/2+1, r, pos));
}
return tmp;
}
int seg2_qry(int x, int l, int r, int pos) {
if(seg2[x] == 0) seg2[x] = 1e9;
int tmp = seg2[x];
if(l != r) {
if(pos <= (l+r)/2) tmp = min(tmp, seg2_qry(x*2, l, (l+r)/2, pos));
else tmp = min(tmp, seg2_qry(x*2+1, (l+r)/2+1, r, pos));
}
return tmp;
}
int main() {
ios::sync_with_stdio(false);
cin >> n;
for(int i=0; i<n; i++) {
v[i].resize(3);
cin >> v[i][0] >> v[i][1] >> v[i][2];
a[0].push_back({v[i][0], i});
a[1].push_back({v[i][1], i});
a[2].push_back({v[i][2], i});
}
sort(a[0].begin(), a[0].end());
sort(a[1].begin(), a[1].end());
sort(a[2].begin(), a[2].end());
for(int i=0; i<3; i++) {
int tmp = 0;
for(int j=0; j<n; j++) {
if(j==0 || a[i][j].first!=a[i][j-1].first) tmp++;
mp[i][tmp] = a[i][j].first;
v[a[i][j].second][i] = tmp;
}
}
sort(v, v+n);
int ans = -1;
int pos = 0;
for(int i=0; i<n; i++) {
if(pos>0) {
if(pos > v[i][1] && seg1_qry(1, 1, n, pos) > v[i][2]) {
//cout << seg1_qry(1, 1, n, l) << " " << seg2_qry(1, 1, n, l) << "\n";
ans = max(ans, mp[2][seg1_qry(1, 1, n, pos)] + mp[1][pos] + mp[0][v[i][0]]);
}
}
if(i<n-1 && v[i][0] != v[i+1][0]) {
for(int j=i; (j>=0 && v[j][0]==v[i][0]); j--) {
seg2_upd(1, 1, n, 1, v[j][1], v[j][2]);
seg1_upd(1, 1, n, v[j][1]+1, n, v[j][2]);
int l,r,mid;
l = v[j][1]+1; r = n;
while(l<r) {
mid = (l+r+1)/2;
if(seg1_qry(1, 1, n, mid) > v[j][2]) r = mid - 1;
else l = mid;
}
if(l<=n && seg1_qry(1, 1, n, l) == v[j][2]) {
r = l; l = v[j][1] + 1;
while(l<r) {
mid = (l+r+1)/2;
if(seg2_qry(1, 1, n, mid) >= v[j][2]) r = mid - 1;
else l = mid;
}
if(seg2_qry(1, 1, n, l) < v[j][2]) {
pos = max(pos, l);
}
}
if(seg1_qry(1, 1, n, v[j][1]) > seg2_qry(1, 1, n, v[j][1])) {
pos = max(pos, v[j][1]);
}
}
}
}
cout << ans << "\n";
}
