#include<iostream>
#include<utility>
#include<map>
using namespace std;

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;
        mp[make_pair(x-1,y)]=mp[make_pair(x-1,y)];
        mp[make_pair(x,y-1)]=mp[make_pair(x,y-1)];
        mp[make_pair(x-1,y-1)]=mp[make_pair(x-1,y-1)];
    }
    int ans =0;
    for(auto x:mp){
        int a = 0;
        a += x.second;
        int s = x.first.first;
        int t = x.first.second;
        if(mp.find(make_pair(s,t+1))!=mp.end())a += mp[make_pair(s,t+1)];
        
        if(mp.find(make_pair(s+1,t+1))!=mp.end())a += mp[make_pair(s+1,t+1)];
        
        if(mp.find(make_pair(s+1,t))!=mp.end())a += mp[make_pair(s+1,t)];
        ans = max(ans,a);
    }
    cout << ans << " / " << 1 << endl; 
    return 0;
}
