#include "bits/stdc++.h"

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

int dx[8] = {1,1,0,-1,-1,-1,0,1,}, dy[8] = {0,1,1,1,0,-1,-1,-1};

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int n; cin >> n;
	vector<P> v(n);
	map<P, int> mp;
	for (int i = 0; i < n; i++) {
		int x, y, w; cin >> x >> y >> w;
		v[i] = P(x, y);
		mp[v[i]] = w;
	}
	int ma = 0;
	for (int i = 0; i < n; i++) {
		int x = v[i].first, y = v[i].second;
		for (int j = 0; j < 8; j += 2) {
			int sum = mp[P(x, y)] + mp[P(x + dx[j], y + dy[j])] + mp[P(x + dx[(j + 1)%8], y + dy[(j + 1)%8])] + mp[P(x + dx[(j + 2)%8], y + dy[(j + 2)%8])];
			ma = max(ma, sum);
		}
	}
	cout << ma <<" / 1" <<endl;
}