#include <bits/stdc++.h>
using namespace std;

using pii = pair<int,int>;
using ll = long long;
#define rep(i, j) for(int i=0; i < (int)(j); i++)
#define repeat(i, j, k) for(int i = (j); i < (int)(k); i++)
#define all(v) v.begin(),v.end()
#define debug(x) cerr << #x << " : " << x << endl

template<class T> bool set_min(T &a, const T &b) { return a > b  ? a = b, true : false; }
template<class T> bool set_max(T &a, const T &b) { return a < b  ? a = b, true : false; }
// vector
template<class T> istream& operator >> (istream &is , vector<T> &v) { for(T &a : v) is >> a; return is; }
template<class T> ostream& operator << (ostream &os , const vector<T> &v) { for(const T &t : v) os << "\t" << t; return os << endl; }
// pair
template<class T, class U> ostream& operator << (ostream &os , const pair<T, U> &v) { return os << "<" << v.first << ", " << v.second << ">"; }

const int INF = 1 << 30;
const ll INFL = 1LL << 60;

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

class Solver {
  public:
    bool solve() {
        int N; cin >> N;
        vector<int> X(N), Y(N), W(N);
        rep(i, N) cin >> X[i] >> Y[i] >> W[i];
        
        map<int, map<int, int>> G;
        rep(i, N) G[Y[i]][X[i]] = W[i];
        
        ll max_a = 0;

        rep(i, N) {
            int x = X[i], y = Y[i];
            for(int x_sign: {1, -1}) {
                for(int y_sign: {1, -1}) {
                    ll sum = 0;
                    rep(j, 4) {                        
                        int xx = x + dx[j] * x_sign;
                        int yy = y + dy[j] * y_sign;
                        sum += G[yy][xx];
                    }
                    set_max(max_a, sum);
                }
            }
        }

        cout << max_a << " / " << 1 << endl;
        
        return 0;
    }
};

int main() {
    Solver s;
    s.solve();
    return 0;
}