#include <algorithm> #include <cstdio> #include <cstdlib> #include <cctype> #include <cmath> #include <iostream> #include <queue> #include <list> #include <map> #include <numeric> #include <set> #include <sstream> #include <string> #include <vector> #include <complex> using namespace std; #define REP(i,a,n) for(int i=(a); i<(int)(n); i++) #define rep(i,n) REP(i,0,n) #define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it) #define ALLOF(c) (c).begin(), (c).end() typedef long long ll; typedef complex<int> P; int outP(const P& p, const P& q){ return imag(conj(p)*q); } struct L : public vector<P> { L(const P& a, const P& b){ push_back(a); push_back(b); } }; bool intersectLS(const L& l, const L& s){return outP(l[1]-l[0],s[0]-l[0])*outP(l[1]-l[0],s[1]-l[0])<=0;} int main(){ int N; cin >> N; vector< pair<int,int> > vall, v1, v2; rep(i,N){ int a, b, c, d; cin >> a >> b >> c >> d; v1.push_back(make_pair(a,b)); v2.push_back(make_pair(c,d)); vall.push_back(make_pair(a,b)); vall.push_back(make_pair(c,d)); } int ret = 0; rep(i,vall.size()){ rep(j,vall.size()){ if(i==j) continue; int tmp = 0; L line(P(vall[i].first, vall[i].second), P(vall[j].first, vall[j].second)); rep(k,N){ L ln(P(v1[k].first, v1[k].second), P(v2[k].first, v2[k].second)); if(intersectLS(line, ln)) tmp++; } ret = max(ret, tmp); } } cout << ret << endl; return 0; }