#include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; i < (int)(n); i++)
using namespace std;
using P = pair<int, int>;

const int dx[] = {0, 1, 1, 0};
const int dy[] = {0, 0, 1, 1};

int main() {
  int n;
  cin >> n;
  map<P, int> mp;
  vector<int> x(n), y(n), w(n);
  REP(i, n) {
    cin >> x[i] >> y[i] >> w[i];
    mp[P(x[i], y[i])] = w[i];
  }
  int ans = 0;
  REP(i, n) {
    REP(j, 4) {
      P cur = {x[i] + dx[j] - 1, y[i] + dy[j] - 1};
      int s = 0;
      REP(k, 4) {
        P nxt = {cur.first + dx[k], cur.second + dy[k]};
        s += mp[nxt];
      }
      ans = max(ans, s);
    }
  }
  cout << ans << " / 1" << endl;
}

