#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <sstream>

using namespace std;

template <typename T>
struct point{
    T x, y;
};

//judge if line AB intersects line CD
template <typename T>
bool intersect(point<T> &a, point<T> &b, point<T> &c, point<T> &d){
    bool ans = 1;
    T s, t;
    s = (a.x - b.x) * (c.y - a.y) - (a.y - b.y) * (c.x - a.x);
    t = (a.x - b.x) * (d.y - a.y) - (a.y - b.y) * (d.x - a.x);
    if (s*t > 0) ans = 0;
    s = (c.x - d.x) * (a.y - c.y) - (c.y - d.y) * (a.x - c.x);
    t = (c.x - d.x) * (b.y - c.y) - (c.y - d.y) * (b.x - c.x);
    if (s*t > 0) ans = 0;
    return ans;
}

int main(){

    long long N, mx=0, M, cnt;
    cin >> N;
    vector<point<long long>> c(N), d(N);
    for (int i=0; i<N; i++) cin >> c[i].x >> c[i].y >> d[i].x >> d[i].y;

    vector<point<long long>> P;
    for (int i=-101; i<=101; i++){
        P.push_back({101, i});
        P.push_back({i, 101});
        P.push_back({-101, i});
        P.push_back({i, -101});
    }
    M = P.size();

    for (int i=0; i<M; i++){
        for (int j=0; j<M; j++){
            cnt = 0;
            for (int k=0; k<N; k++){
                if (intersect(P[i], P[j], c[k], d[k])) cnt++;
            }
            mx = max(mx, cnt);
        }
    }

    cout << mx << endl;

    return 0;
}