#include <bits/stdc++.h>
using namespace std;
using ll = long long;
void solve(){
int n;
cin >> n;
map<int, int> posx, posy;
vector<int> x(n), y(n), w(n);
for(int i = 0; i < n; i++){
cin >> x[i] >> y[i] >> w[i];
posx[x[i]] = 0;
posy[y[i]] = 0;
}
int xc = 0, yc = posy.size();
for(auto &[i, j] : posx) j = xc++;
for(auto &[i, j] : posy) j = --yc;
vector<vector<ll>> arr(posy.size(), vector<ll>(posx.size())), pref(posy.size() + 1, vector<ll>(posx.size() + 1));
for(int i = 0; i < n; i++){
arr[posy[y[i]]][posx[x[i]]] = w[i];
}
for(int i = 1; i <= posy.size(); i++){
for(int j = 1; j <= posx.size(); j++){
pref[i][j] = pref[i - 1][j] + pref[i][j - 1] + arr[i - 1][j - 1] - pref[i - 1][j - 1];
}
}
ll ans = 0;
for(int i = 1; i <= posy.size(); i++){
for(int j = i; j <= posy.size(); j++){
ll q = pref[j][posx.size()] - pref[i - 1][posx.size()];
ans = max(ans, q);
}
}
for(int i = 1; i <= posx.size(); i++){
for(int j = i; j <= posx.size(); j++){
ll q = pref[posy.size()][j] - pref[posy.size()][i - 1];
ans = max(ans, q);
}
}
cout << ans;
}
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
solve();
return 0;
}
