#include // c #include // io #include #include #include #include // container #include #include #include #include #include #include // other #include #include #include #include #include using namespace std; typedef long long ll; typedef unsigned long long ull; #define ALL(c) (begin(c)),(end(c)) #define REP(i,n) FOR(i,0,n) #define REPr(i,n) FORr(i,0,n) #define FOR(i,l,r) for(int i=(int)(l);i<(int)(r);++i) #define FORr(i,l,r) for(int i=(int)(r)-1;i>=(int)(l);--i) #define EACH(it,o) for(auto it = (o).begin(); it != (o).end(); ++it) #define IN(l,v,r) ((l)<=(v) && (v)<(r)) #define UNIQUE(v) v.erase(unique(ALL(v)),v.end()) //debug #define DUMP(x) cerr << #x << " = " << (x) #define LINE() cerr<< " (L" << __LINE__ << ")" class range { private: struct Iter{ int v; int operator*(){return v;} bool operator!=(Iter& itr) {return v < itr.v;} void operator++() {++v;} }; Iter i, n; public: range(int n) : i({0}), n({n}) {} range(int i, int n) : i({i}), n({n}) {} Iter& begin() {return i;} Iter& end() {return n;} }; //input template istream& operator >> (istream& is,pair& p){is>>p.first>>p.second;return is;} template istream& operator >> (istream& is,tuple& t){is >> get<0>(t);return is;} template istream& operator >> (istream& is,tuple& t){is >> get<0>(t) >> get<1>(t);return is;} template istream& operator >> (istream& is,tuple& t){is >>get<0>(t)>>get<1>(t)>>get<2>(t);return is;} template istream& operator >> (istream& is,tuple& t){is >> get<0>(t)>>get<1>(t)>>get<2>(t)>>get<3>(t);return is;} template istream& operator >> (istream& is, const tuple& t){is >> get<0>(t) >> get<1>(t) >> get<2>(t) >> get<3>(t) >> get<4>(t);return is;} template istream& operator >> (istream& is, const tuple& t){is >> get<0>(t) >> get<1>(t) >> get<2>(t) >> get<3>(t) >> get<4>(t) >> get<5>(t);return is;} template istream& operator >> (istream& is, const tuple& t){is >> get<0>(t) >> get<1>(t) >> get<2>(t) >> get<3>(t) >> get<4>(t) >> get<5>(t) >> get<6>(t);return is;} template istream& operator >> (istream& is,vector& as){REP(i,as.size())is >>as[i];return is;} //output template ostream& operator << (ostream& os, const set& ss){for(auto a:ss){if(a!=ss.begin())os<<" "; os< ostream& operator << (ostream& os, const pair& p){os< ostream& operator << (ostream& os, const map& m){bool isF=true;for(auto& p:m){if(!isF)os< ostream& operator << (ostream& os, const tuple& t){os << get<0>(t);return os;} template ostream& operator << (ostream& os, const tuple& t){os << get<0>(t)<<" "<(t);return os;} template ostream& operator << (ostream& os, const tuple& t){os << get<0>(t)<<" "<(t)<<" "<(t);return os;} template ostream& operator << (ostream& os, const tuple& t){os << get<0>(t)<<" "<(t)<<" "<(t)<<" "<(t);return os;} template ostream& operator << (ostream& os, const tuple& t){os << get<0>(t)<<" "<(t)<<" "<(t)<<" "<(t)<<" "<(t);return os;} template ostream& operator << (ostream& os, const tuple& t){os << get<0>(t)<<" "<(t)<<" "<(t)<<" "<(t)<<" "<(t)<<" "<(t);return os;} template ostream& operator << (ostream& os, const tuple& t){os << get<0>(t)<<" "<(t)<<" "<(t)<<" "<(t)<<" "<(t)<<" "<(t)<<" "<(t);return os;} template ostream& operator << (ostream& os, const vector& as){REP(i,as.size()){if(i!=0)os<<" "; os< ostream& operator << (ostream& os, const vector>& as){REP(i,as.size()){if(i!=0)os< T INF(){assert(false);}; template<> int INF(){return 1<<28;}; template<> ll INF(){return 1LL<<58;}; template<> double INF(){return 1e16;}; template<> long double INF(){return 1e16;}; template T EPS(){assert(false);}; template<> int EPS(){return 1;}; template<> ll EPS(){return 1LL;}; template<> double EPS(){return 1e-8;}; template<> long double EPS(){return 1e-8;}; template T pmod(T v,U M){return (v%M+M)%M;} namespace _double_tmpl{ typedef long double D; static constexpr D Ae=0; D A(D a,D b){return a+b;}D Ainv(D a){return -a;} D S(D a,D b){return A(a,Ainv(b));} static constexpr D Me=1; D M(D a,D b){return a*b;}D Minv(D a){return 1.0/a;}; int sig(D a,D b=0){return a()?-1:a>b+EPS()?1:0;} template bool eq(const T& a,const T& b){return sig(abs(a-b))==0;} D pfmod(D v,D MOD=2*M_PI){return fmod(fmod(v,MOD)+MOD,MOD);} //[0,PI) D AbsArg(D a){ D ret=pfmod(max(a,-a),2*M_PI);return min(ret,2*M_PI-ret); } } using namespace _double_tmpl; typedef complex P,Vec; const P O=P(0,0); #define X real() #define Y imag() istream& operator >> (istream& is,complex& p){ D x,y;is >> x >> y;p=P(x,y);return is; } bool compX (const P& a,const P& b){return !eq(a.X,b.X)?sig(a.X,b.X)<0:sig(a.Y,b.Y)<0;} bool compY (const P& a,const P& b){return !eq(a.Y,b.Y)?sig(a.Y,b.Y)<0:sig(a.X,b.X)<0;} // a×b D cross(const Vec& a,const Vec& b){return imag(conj(a)*b);} // a・b D dot(const Vec&a,const Vec& b) {return real(conj(a)*b);} int ccw(const P& a,P b,P c){ b -= a; c -= a; if (sig(cross(b,c))>0) return +1; // counter clockwise if (sig(cross(b,c))<0) return -1; // clockwise if (sig(dot(b,c)) < 0) return +2; // c--a--b on line if (sig(norm(b),norm(c))<0) return -2; // a--b--c on line return 0; } namespace std{ bool operator < (const P& a,const P& b){return compX(a,b);} bool operator == (const P& a,const P& b){return eq(a,b);} }; namespace _L{ struct L : public vector

{ P vec() const {return this->at(1)-this->at(0);} L(const P &a, const P &b){push_back(a); push_back(b);} L(){push_back(P(0,0));push_back(P(0,0));} }; istream& operator >> (istream& is,L& l){P s,t;is >> s >> t;l=L(s,t);return is;} bool isIntersectLL(const L &l, const L &m) { return sig(cross(l.vec(), m.vec()))!=0 || // non-parallel sig(cross(l.vec(), m[0]-l[0])) ==0; // same line } bool isIntersectLS(const L &l, const L &s) { return sig(cross(l.vec(), s[0]-l[0])* // s[0] is left of l cross(l.vec(), s[1]-l[0]))<=0; // s[1] is right of l } bool isIntersectLP(const L &l, const P &p) { return sig(cross(l[1]-p, l[0]-p))==0; } // verified by ACAC003 B // http://judge.u-aizu.ac.jp/onlinejudge/creview.jsp?rid=899178&cid=ACAC003 bool isIntersectSS(const L &s, const L &t) { return ccw(s[0],s[1],t[0])*ccw(s[0],s[1],t[1]) <= 0 && ccw(t[0],t[1],s[0])*ccw(t[0],t[1],s[1]) <= 0; } bool isIntersectSP(const L &s, const P &p) { return sig(abs(s[0]-p)+abs(s[1]-p),abs(s[1]-s[0])) <=0; // triangle inequality } // 直線へ射影した時の点 // verified by AOJLIB // http://judge.u-aizu.ac.jp/onlinejudge/review.jsp?rid=1092212 P projection(const L &l, const P &p) { D t = dot(p-l[0],l.vec()) / norm(l.vec()); return l[0] + t * l.vec(); } //対称な点 // verified by AOJLIB // http://judge.u-aizu.ac.jp/onlinejudge/review.jsp?rid=1092214 P reflection(const L &l, const P &p) { return p + 2.0L * (projection(l, p) - p); } D distanceLP(const L &l, const P &p) { return abs(p - projection(l, p)); } D distanceLL(const L &l, const L &m) { return isIntersectLL(l, m) ? 0 : distanceLP(l, m[0]); } D distanceLS(const L &l, const L &s) { if (isIntersectLS(l, s)) return 0; return min(distanceLP(l, s[0]), distanceLP(l, s[1])); } D distanceSP(const L &s, const P &p) { const P r = projection(s, p); if (isIntersectSP(s, r)) return abs(r - p); return min(abs(s[0] - p), abs(s[1] - p)); } D distanceSS(const L &s, const L &t) { if (isIntersectSS(s, t)) return 0; return min(min(distanceSP(s, t[0]), distanceSP(s, t[1])), min(distanceSP(t, s[0]), distanceSP(t, s[1]))); } // 交点計算 // verified by AOJLIB // http://judge.u-aizu.ac.jp/onlinejudge/review.jsp?rid=1092231 P crosspoint(const L &l, const L &m) { D A = cross(l.vec(), m.vec()),B = cross(l.vec(), l[1] - m[0]); if (sig(A)==0 && sig(B)==0) return m[0]; // same line assert(sig(A)!=0);//err -> 交点を持たない. return m[0] + B / A * (m[1] - m[0]); } } using namespace _L; ll MOD =1e9+7; class Main{ public: void run(){ int N;cin >> N; vector

ps(2*N);cin >> ps; vector ls(N); for(int i:range(N))ls[i]=L(ps[2*i],ps[2*i+1]); int res = 0; for(int i:range(2*N))for(int j:range(2*N))if(ps[i]!=ps[j]){ L l=L(ps[i],ps[j]); int c = 0; for(int k:range(N))if(isIntersectLS(l,ls[k]))c++; res=max(res,c); } cout << res <