#include <algorithm>
#include <cmath>
#include <climits>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <cassert>
#include <functional>

using namespace std;

#define LOG(...) printf(__VA_ARGS__)
//#define LOG(...)
#define FOR(i,a,b) for(int i=(int)(a);i<(int)(b);++i)
#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())
#define RSORT(c) sort((c).rbegin(),(c).rend())
#define CLR(a) memset((a), 0 ,sizeof(a))

typedef long long ll;
typedef unsigned long long ull;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vb> vvb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

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

const int dx8[] = { -1,-1, 0, 1,1,1, 0,-1 }; const int dy8[] = { 0,1,1, 1, 0, -1,-1,-1 };
struct UnionFind {
	vector<int> v;
	UnionFind(int n) : v(n)  { for (int i = 0; i < n; i++) v[i] = i; }
	int  find(int x)         { return v[x] == x ? x : v[x] = find(v[x]); }
	void unite(int x, int y) { v[find(x)] = find(y); }
};

int main() {
	int n;
	cin >> n;
	map<pii, int> rab;
	REP(i, n) {
		int a, b, w;
		cin >> a >> b >> w;
		rab[{a, b}] = w;
	}
	int ans = 0;
	for (auto it = rab.begin();it != rab.end();it++) {
		int ma = 0;
		REP(j,4) {
			int sum=0;
			sum += it->second;
			REP(k,3)
			if (rab.find({ it->first.first + dx8[(j * 2 + k) % 8],it->first.second + dy8[(j * 2 + k) % 8] }) != rab.end()) {
				sum += rab[{ it->first.first + dx8[(j * 2 + k) % 8], it->first.second + dy8[(j * 2 + k) % 8] }];
			}

			ma = max(sum,ma);
		}
		ans = max(ans, ma);
	}
	cout << ans << " / 1" << endl;
}