#include <bits/stdc++.h>
//#define int long long
#define ll long long
#define all(lpv) lpv.begin(), lpv.end()
#define pot(x, y) lower_bound(x.begin(), x.end(), y) - x.begin() + 1
using namespace std;
typedef pair<int,int> pii;
const int N = 2e5 + 5;
const int oo = -1e9;
int n, a[N], b[N], c[N];
vector<int> rrh, rz, px;
struct ST{
int m;
struct node {
int mx[2], last[2], kq[2], we[2];
} st[N << 2];
void build(int i,int l,int r) {
if(l == r) {
for(int j = 0; j <= 1; j ++) {
st[i].mx[j] = oo;
st[i].last[j] = -1;
st[i].kq[j] = oo;
st[i].we[j] = -1;
}
return;
}
int mid = (l + r) / 2;
build(i << 1, l, mid);
build(i << 1|1, mid + 1, r);
for(int j = 0; j <= 1; j ++) {
st[i].mx[j] = oo;
st[i].last[j] = -1;
st[i].kq[j] = oo;
st[i].we[j] = -1;
}
}
void collect(int& fi, int& tfi, int& se, int& tse,int val,int x) {
if(x == tfi && tfi != -1) fi = max(fi, val);
else if(x == tse && tse != -1) se = max(se, val);
else {
if(fi < val) {
se = fi, tse = tfi;
fi = val;
tfi = x;
} else if(se < val) {
se = val;
tse = x;
}
}
}
void add(int i,int l,int r,int u,int val,int x) {
if(l > r || r < u || u < l) return;
if(l == r) {
collect(st[i].mx[0], st[i].last[0], st[i].mx[1], st[i].last[1], val, x);
return;
}
int mid = (l + r) / 2;
add(i << 1, l, mid, u, val, x);
add(i << 1|1, mid + 1, r, u, val, x);
collect(st[i].mx[0], st[i].last[0], st[i].mx[1], st[i].last[1], val, x);
}
int ret[2], t[2];
void get(int i,int l,int r,int u,int v,int val,int x) {
if(l > r || r < u || v < l) return;
if(u <= l && r <= v) {
if(st[i].last[0] > x && st[i].last[0] != -1) collect(ret[0], t[0], ret[1], t[1], st[i].mx[0] + val, st[i].last[0]);
if(st[i].last[1] > x && st[i].last[1] != -1) collect(ret[0], t[0], ret[1], t[1], st[i].mx[1] + val, st[i].last[1]);
return;
}
int mid = (l + r) / 2;
get(i << 1, l, mid, u, v, val, x);
get(i << 1|1, mid + 1, r, u, v, val, x);
}
tuple<int,int,int,int> pre(int pos,int val,int x) {
ret[0] = ret[1] = oo;
t[0] = t[1] = oo;
get(1, 1, m, 1, pos - 1, val, x);
return {ret[0], t[0], ret[1], t[1]};
}
void update(int i,int l,int r,int u,int fi,int tfi,int se,int tse) {
if(l > r || r < u || u < l) return;
if(l == r) {
collect(st[i].kq[0], st[i].we[0], st[i].kq[1], st[i].we[1], fi, tfi);
collect(st[i].kq[0], st[i].we[0], st[i].kq[1], st[i].we[1], se, tse);
return;
}
int mid = (l + r) / 2;
update(i << 1, l, mid, u, fi, tfi, se, tse);
update(i << 1|1, mid + 1, r, u, fi, tfi, se, tse);
collect(st[i].kq[0], st[i].we[0], st[i].kq[1], st[i].we[1], fi, tfi);
collect(st[i].kq[0], st[i].we[0], st[i].kq[1], st[i].we[1], se, tse);
}
void query(int i,int l,int r,int u,int v,int val,int x) {
if(l > r || r < u || v < l) return;
if(u <= l && r <= v) {
if(st[i].we[0] > x && st[i].we[0] != -1) collect(ret[0], t[0], ret[1], t[1], st[i].kq[0] + val, st[i].we[0]);
if(st[i].we[1] > x && st[i].we[1] != -1) collect(ret[0], t[0], ret[1], t[1], st[i].kq[1] + val, st[i].we[1]);
return;
}
int mid = (l + r) / 2;
query(i << 1, l, mid, u, v, val, x);
query(i << 1|1, mid + 1, r, u, v, val, x);
}
int pick(int pos,int val,int x) {
ret[0] = ret[1] = oo;
t[0] = t[1] = oo;
query(1, 1, m, pos + 1, m, val, x);
return max(ret[0], ret[1]);
}
} Y, Z;
// 0 -> 0 0
// 1 -> 1 0
// 2 -> 0 1
// 3 -> 1 1
int ans = -1;
vector<int> Q[N];
void solve() {
px.clear();
rrh.clear();
rz.clear();
for(int i = 1; i <= n; i ++) {
px.push_back(a[i]);
rrh.push_back(b[i]);
rz.push_back(c[i]);
}
sort(all(px)); px.resize(unique(all(px)) - px.begin());
sort(all(rrh)); rrh.resize(unique(all(rrh)) - rrh.begin());
sort(all(rz)); rz.resize(unique(all(rz)) - rz.begin());
for(int i = 1; i <= n; i ++) {
int tmp = pot(px, a[i]);
Q[tmp].push_back(i);
}
int Max = oo;
Y.m = (int)rrh.size();
Z.m = (int)rz.size();
Y.build(1, 1, Y.m);
Z.build(1, 1, Z.m);
for(int k = 1; k <= (int)px.size(); k ++) {
for(auto j : Q[k]) {
int pos_b = pot(rrh, b[j]);
int pos_c = pot(rz, c[j]);
int val = oo;
val = Y.pick(pos_b, a[j], c[j]);
if(val != oo) ans = max(ans, val);
val = Z.pick(pos_c, a[j], b[j]);
if(val != oo) ans = max(ans, val);
}
// update add
for(auto j : Q[k]) {
int pos_b = pot(rrh, b[j]);
int pos_c = pot(rz, c[j]);
auto tmp = Y.pre(pos_b, b[j], c[j]);
int x, y, z, t; tie(x, y, z, t) = tmp;
if(x != oo) Y.update(1, 1, Y.m, pos_b, x, y, z, t);
tmp = Z.pre(pos_c, c[j], b[j]);
tie(x, y, z, t) = tmp;
if(x != oo) Z.update(1, 1, Z.m, pos_c, x, y, z, t);
Y.add(1, 1, Y.m, pos_b, c[j], c[j]);
Z.add(1, 1, Z.m, pos_c, b[j], b[j]);
}
Q[k].clear();
}
}
signed main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define task "v"
if(fopen(task ".inp","r")) {
freopen(task ".inp","r",stdin);
freopen(task ".out","w",stdout);
}
cin >> n;
for(int i = 1; i <= n; i ++) {
cin >> a[i] >> b[i] >> c[i];
}
solve();
for(int i = 1; i <= n; i ++) swap(a[i], b[i]);
solve();
for(int i = 1; i <= n; i ++) swap(a[i], c[i]);
solve();
cout << ans;
}
