#include <bits/stdc++.h>
using namespace std;
vector<int> dy = {1, 0, -1, 0};
vector<int> dx = {0, 1, 0, -1};
int main(){
  int N;
  cin >> N;
  map<pair<int, int>, int> mp;
  for (int i = 0; i < N; i++){
    int x, y, w;
    cin >> x >> y >> w;
    mp[make_pair(x, y)] = w;
  }
  long long ans = 0;
  for (auto P : mp){
    int x = P.first.first;
    int y = P.first.second;
    for (int i = -1; i <= 1; i++){
      for (int j = -1; j <= 1; j++){
        long long sum = 0;
        for (int k = 0; k < 2; k++){
          for (int l = 0; l < 2; l++){
            if (mp.count(make_pair(x - i + k, y - j + l))){
              sum += mp[make_pair(x - i + k, y - j + l)];
            }
          }
        }
        ans = max(ans, sum);
      }
    }
  }
  cout << ans << " / " << 1 << endl;
}
