#include <bits/stdc++.h>
#define lf (h << 1)
#define mf ((l + r) >> 1)
#define rf ((h << 1) | 1)
#define tree int h, int l, int r
#define left lf, l, mf
#define right rf, mf + 1, r
#define ll long long
#define pb push_back
#define f first
#define s second
using namespace std;
const int N = 150005;
int n, x[N], y[N], z[N], Ox[N], Oy[N], Oz[N];
vector < int > vx[N], vy[N], vz[N];
vector < pair < int , int > > G[N];
int v[5 * N][3];
inline void upd(tree, int id, int vl, bool tp) {
if (r < id || id < l) return ;
if (l == id && id == r) {
v[h][tp] = max(v[h][tp], vl);
return ;
}
upd(left, id, vl, tp);
upd(right, id, vl, tp);
v[h][tp] = max(v[lf][tp], v[rf][tp]);
}
inline int get(tree, int L, int R, bool tp) {
if (r < L || R < l) return 0;
if (L <= l && r <= R) return v[h][tp];
return max(get(left, L, R, tp), get(right, L, R, tp));
}
main () {
ios::sync_with_stdio(false);
cin.tie(NULL), cout.tie(NULL);
cin >> n;
vector < int > sx, sy, sz, s;
map < int , int > fx, fy, fz;
for (int i = 1; i <= n; ++i) {
cin >> x[i] >> y[i] >> z[i];
sx.pb(x[i]);
sy.pb(y[i]);
sz.pb(z[i]);
s.pb(i);
}
sort(sx.begin(), sx.end());
sort(sy.begin(), sy.end());
sort(sz.begin(), sz.end());
sx.erase(unique(sx.begin(), sx.end()), sx.end());
sy.erase(unique(sy.begin(), sy.end()), sy.end());
sz.erase(unique(sz.begin(), sz.end()), sz.end());
for (int i = 0; i < sx.size(); ++i) fx[sx[i]] = i + 1, Ox[i + 1] = sx[i];
for (int i = 0; i < sy.size(); ++i) fy[sy[i]] = i + 1, Oy[i + 1] = sy[i];
for (int i = 0; i < sz.size(); ++i) fz[sz[i]] = i + 1, Oz[i + 1] = sz[i];
for (int i = 1; i <= n; ++i) {
x[i] = fx[x[i]];
y[i] = fy[y[i]];
z[i] = fz[z[i]];
}
for (int i = 1; i <= n; ++i) {
vx[x[i]].pb(i);
vy[y[i]].pb(i);
vz[z[i]].pb(i);
}
for (int i = 1; i <= sx.size(); ++i) {
for (int j = 0; j < vx[i].size(); ++j) {
int id = vx[i][j];
upd(1, 1, sy.size(), y[id], z[id], 0);
upd(1, 1, sz.size(), z[id], y[id], 1);
}
for (int j = 0; j < vx[i].size(); ++j) {
int id = vx[i][j];
int Z = get(1, 1, sy.size(), 1, y[id] - 1, 0);
int Y = get(1, 1, sz.size(), 1, z[id] - 1, 1);
if (z[id] < Z) {
G[y[id]].pb({x[id], Z});
}
if (y[id] < Y) {
G[Y].pb({x[id], z[id]});
}
}
}
for (int i = 1; i <= 5 * n; ++i) {
v[i][0] = v[i][1] = 0;
}
int ans = -1;
for (int i = 1; i <= sy.size(); ++i) {
for (int j = 0; j < G[i].size(); ++j) {
int xid = G[i][j].f, zid = G[i][j].s;
int X = get(1, 1, sz.size(), 1, zid - 1, 1);
if (xid < X) {
ans = max(ans, Ox[X] + Oy[i] + Oz[zid]);
}
}
for (int j = 0; j < vy[i].size(); ++j) {
int id = vy[i][j];
upd(1, 1, sz.size(), z[id], x[id], 1);
}
}
cout << ans << "\n";
}
