#include "bits/stdc++.h"
using namespace std;
#ifdef duc_debug
#include "bits/debug.h"
#else
#define debug(...)
#endif
const int maxn = 150005;
int n;
struct contestant {
int x, y, z;
} a[maxn];
int ord[maxn];
void solve() {
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, [](const contestant &x, const contestant &y) -> bool {
return x.x < y.x;
});
int res = -1;
int y = 0, z = 0;
set<pair<int, int>> s;
for (int i = 1; i <= n; ++i) {
int cur = 0;
while (i + cur <= n and a[i].x == a[i + cur].x) {
++cur;
continue;
}
for (int j = i; j < i + cur; ++j) {
if (y > a[j].y and z > a[j].z) {
res = max(res, y + z + a[j].x);
}
}
for (int j = i; j < i + cur; ++j) {
auto it = s.lower_bound(make_pair(a[j].y + 1, 0));
while (it != s.end()) {
if (it->second >= a[j].z) {
break;
}
y = max(y, it->first);
z = max(z, it->second);
it = s.erase(it);
}
it = s.lower_bound(make_pair(a[j].y, 0));
while (it != s.begin()) {
it--;
if (it->second <= a[j].z) {
break;
}
y = max(y, it->first);
z = max(z, it->second);
it = s.erase(it);
}
if (a[j].y < y || a[j].z < z) {
y = max(a[j].y, y);
z = max(a[j].z, z);
} else {
s.insert(make_pair(a[j].y, a[j].z));
}
}
i = i + cur - 1;
}
cout << res;
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
solve();
return 0;
}
