Problem: <image>


As shown in the figure above, cut a convex polygon g by a line p1p2 and print the area of the cut polygon which is on the left-hand side of the line.

g is represented by a sequence of points p1, p2,..., pn where line segments connecting pi and pi+1 (1 ≤ i ≤ n−1) are sides of the convex polygon. The line segment connecting pn and p1 is also a side of the polygon.

Constraints

* 3 ≤ n ≤ 100
* 1 ≤ q ≤ 100
* -10000 ≤ xi, yi ≤ 10000
* -10000 ≤ p1x,p1y,p2x,p2y ≤ 10000
* No point in g will occur more than once.
* p1 ≠ p2

Input

The input is given in the following format:


g (the sequence of the points of the polygon)
q (the number of queries = the number of target lines)
1st query
2nd query
:
qth query


g is given as a sequence of points p1,..., pn in the following format:


n
x1 y1
x2 y2
:
xn yn


The first integer n is the number of points. The coordinate of the i-th point pi is given by two integers xi and yi. The coordinates of points are given in the order of counter-clockwise visit of them. Note that all interior angles of given convex polygons are less than or equal to 180.

For each query, a line represented by two points p1 and p2 is given. The coordinates of the points are given by four integers p1x, p1y, p2x and p2y.

Output

For each query, print the area of the cut polygon. The output values should be in a decimal fraction with an error less than 0.00001.

Example

Input

4
1 1
4 1
4 3
1 3
2
2 0 2 4
2 4 2 0


Output

2.00000000
4.00000000

Solution (in CPP):

Solution:
using namespace std;
#include<iostream>
#include<algorithm>
#include<vector>
#include<cmath>
#include<iomanip>
const double EPS=1e-10;
bool eq(double a,double b){return abs(a-b)<EPS;}
struct Point{
	double x,y;
	Point(double x_=0,double y_=0):x(x_),y(y_){}
	Point operator-()const{return Point(-x,-y);}
	Point operator+(const Point&p)const{return Point(x+p.x,y+p.y);}
	Point operator-(const Point&p)const{return Point(x-p.x,y-p.y);}
	Point operator*(const double k)const{return Point(x*k,y*k);}
	Point operator/(const double k)const{return Point(x/k,y/k);}
	bool operator<(const Point&p)const{return eq(x,p.x)?y<p.y:x<p.x;}
	bool operator==(const Point&p)const{return eq(x,p.x)&&eq(y,p.y);}
};
istream&operator>>(istream&is,Point&p){return is>>p.x>>p.y;}
ostream&operator<<(ostream&os,const Point&p){return os<<fixed<<setprecision(9)<<p.x<<' '<<p.y;}
struct Line{
	Point p1,p2;
	Line(Point p1_=Point(),Point p2_=Point()):p1(p1_),p2(p2_){}
};
struct Segment:Line{
	Segment(Point p1_=Point(),Point p2_=Point()):Line(p1_,p2_){}
};
struct Circle{
	Point o;
	double r;
	Circle(Point o_=Point(),double r_=0):o(o_),r(r_){}
};
using Polygon=vector<Point>;
//function list begin
Point vec(const Line&);
double norm(const Point&);
double norm(const Line&);
double abs(const Point&);
double abs(const Line&);
double arg(const Point&);
double arg(const Line&);
double arg(const Point&,const Point&,const Point&);//a->b->c
double dot(const Point&,const Point&);
double cross(const Point&,const Point&);
Point polar(const double,const double);
Point rotate(const Point&,const double);
enum{ONLINE_FRONT=-2,CLOCKWISE=-1,ON_SEGMENT=0,COUNTER_CLOCKWISE=1,ONLINE_BACK=2};
int ccw(const Point&,const Point&,const Point&);
int ccw(const Line&,const Point&);
bool orthogonal(const Point&,const Point&);
bool orthogonal(const Line&,const Line&);
bool parallel(const Point&,const Point&);
bool parallel(const Line&,const Line&);
bool intersect(const Line&,const Point&);
bool intersect(const Line&,const Line&);
bool intersect(const Segment&,const Point&);
bool intersect(const Segment&,const Segment&);
bool intersect(const Line&,const Segment&);
bool intersect(const Segment&,const Line&);
bool intersect(const Circle&,const Point&);
int intersect(const Circle&,const Line&);//count contacts
int intersect(const Circle&,const Segment&);
int intersect(const Circle&,const Circle&);
double distance(const Point&,const Point&);
double distance(const Line&,const Point&);
double distance(const Line&,const Line&);
double distance(const Segment&,const Point&);
double distance(const Segment&,const Segment&);
double distance(const Line&,const Segment&);
double distance(const Segment&,const Line&);
double distance(const Circle&,const Point&);
double distance(const Circle&,const Line&);
double distance(const Circle&,const Segment&);
double distance(const Circle&,const Circle&);
Point projection(const Line&,const Point&);
Point reflection(const Line&,const Point&);
Point crosspoint(const Line&,const Line&);
pair<Point,Point>crosspoint(const Circle&,const Line&);
pair<Point,Point>crosspoint(const Circle&,const Segment&);
pair<Point,Point>crosspoint(const Circle&,const Circle&);
pair<Point,Point>tangent(const Circle&,const Point&);
vector<Line>tangent(const Circle&,const Circle&);
bool is_convex(const Polygon&);
Polygon convex_full(Polygon,bool=false);
enum{OUT,ON,IN};
int contain(const Polygon&,const Point&);
int contain(const Circle&,const Point&);
Polygon convex_cut(const Polygon&,const Line&);
double area(const Polygon&);
double area(const Polygon&,const Line&);
double area(const Polygon&,const Circle&);
//function list end
Point vec(const Line&s){return s.p2-s.p1;}
double norm(const Point&p){return p.x*p.x+p.y*p.y;}
double norm(const Line&s){return norm(vec(s));}
double abs(const Point&p){return hypot(p.x,p.y);}
double abs(const Line&s){return abs(vec(s));}
double arg(const Point&p){return atan2(p.y,p.x);}
double arg(const Line&s){return arg(vec(s));}
double arg(const Point&a,const Point&b,const Point&c){
	double A=arg(b-a),B=arg(c-b);
	double theta=abs(A-B);
	return min(theta,2*M_PI-theta);
}
double dot(const Point&a,const Point&b){return a.x*b.x+a.y*b.y;}
double cross(const Point&a,const Point&b){return a.x*b.y-a.y*b.x;}
Point polar(const double r,const double theta){return Point(cos(theta),sin(theta))*r;}
Point rotate(const Point&p,const double theta){
	return Point(p.x*cos(theta)-p.y*sin(theta),p.x*sin(theta)+p.y*cos(theta));
}
int ccw(const Point&a,const Point&b,const Point&c){
	Point p=b-a,q=c-a;
	return cross(p,q)>EPS?COUNTER_CLOCKWISE
		:cross(p,q)<-EPS?CLOCKWISE
		:dot(p,q)<0?ONLINE_BACK
		:norm(p)<norm(q)?ONLINE_FRONT
		:ON_SEGMENT;
}
int ccw(const Line&s,const Point&p){return ccw(s.p1,s.p2,p);}
bool orthogonal(const Point&a,const Point&b){return eq(dot(a,b),0);}
bool orthogonal(const Line&s,const Line&t){return orthogonal(vec(s),vec(t));}
bool parallel(const Point&a,const Point&b){return eq(cross(a,b),0);}
bool parallel(const Line&s,const Line&t){return parallel(vec(s),vec(t));}
bool intersect(const Line&s,const Point&p){return eq(cross(vec(s),p-s.p1),0);}
bool intersect(const Line&s,const Line&t){return !parallel(s,t)||intersect(s,t.p1);}
bool intersect(const Segment&s,const Point&p){return ccw(s,p)==ON_SEGMENT;}
bool intersect(const Segment&s,const Segment&t){
	return ccw(s,t.p1)*ccw(s,t.p2)<=0&&ccw(t,s.p1)*ccw(t,s.p2)<=0;
}
bool intersect(const Line&s,const Segment&t){
	return cross(vec(s),t.p1-s.p1)*cross(vec(s),t.p2-s.p1)<EPS;
}
bool intersect(const Segment&s,const Line&t){return intersect(t,s);}
bool intersect(const Circle&c,const Point&p){return eq(distance(c.o,p),c.r);}
int intersect(const Circle&c,const Line&s){
	double d=distance(s,c.o);
	return eq(d,c.r)?1:d<c.r?2:0;
}
int intersect(const Circle&c,const Segment&s){
	Point h=projection(s,c.o);
	double d1=distance(c.o,s.p1),d2=distance(c.o,s.p2);
	return distance(c.o,h)>c.r+EPS?0
		:d1<c.r-EPS&&d2<c.r-EPS?0
		:d1<c.r-EPS&&d2>c.r+EPS||d1>c.r+EPS&&d2<c.r-EPS?1
		:intersect(s,h)?distance(c.o,h)<c.r-EPS?2:1
		:0;
}
int intersect(const Circle&a,const Circle&b){
	double d=distance(a.o,b.o);
	return eq(d,a.r+b.r)?3:d>a.r+b.r?4:eq(d,abs(a.r-b.r))?1:d>abs(a.r-b.r)?2:0;
}
double distance(const Point&a,const Point&b){return abs(a-b);}
double distance(const Line&s,const Point&p){return distance(p,projection(s,p));}
double distance(const Line&s,const Line&t){return intersect(s,t)?0:distance(s,t.p1);}
double distance(const Segment&s,const Point&p){
	return distance(p,
		dot(vec(s),p-s.p1)<0?s.p1
		:dot(-vec(s),p-s.p2)<0?s.p2
		:projection(s,p)
	);
}
double distance(const Segment&s,const Segment&t){
	return intersect(s,t)?0:min({
		distance(s,t.p1),distance(s,t.p2),
		distance(t,s.p1),distance(t,s.p2)
	});
}
double distance(const Line&s,const Segment&t){
	return intersect(s,t)?0:min(distance(s,t.p1),distance(s,t.p2));
}
double distance(const Segment&s,const Line&t){return distance(t,s);}
double distance(const Circle&c,const Point&p){return abs(distance(c.o,p)-c.r);}
double distance(const Circle&c,const Line&s){return max(distance(s,c.o)-c.r,0.);}
double distance(const Circle&c,const Segment&s){
	Point h=projection(s,c.o);
	double d1=distance(c.o,s.p1),d2=distance(c.o,s.p2);
	return intersect(c,s)?0
		:d1<c.r-EPS&&d2<c.r-EPS?c.r-max(d1,d2)
		:intersect(s,h)?distance(c.o,h)-c.r
		:min(distance(c.o,s.p1),distance(c.o,s.p2))-c.r;
}
double distance(const Circle&a,const Circle&b){return max(distance(a.o,b.o)-a.r-b.r,0.);}
Point projection(const Line&s,const Point&p){
	return s.p1+vec(s)*dot(p-s.p1,vec(s))/norm(s);
}
Point reflection(const Line&s,const Point&p){return projection(s,p)*2-p;}
Point crosspoint(const Line&s,const Line&t){
	double d1=abs(cross(vec(s),t.p1-s.p1));
	double d2=abs(cross(vec(s),t.p2-s.p1));
	return t.p1+vec(t)*(d1/(d1+d2));
}
pair<Point,Point>crosspoint(const Circle&c,const Line&s){
	Point h=projection(s,c.o);
	Point e=vec(s)/abs(s)*sqrt(c.r*c.r-norm(h-c.o));
	return minmax(h-e,h+e);
}
pair<Point,Point>crosspoint(const Circle&c,const Segment&s){
	pair<Point,Point>p=crosspoint(c,Line(s));
	return intersect(c,s)==2?p
		:intersect(s,p.first)?make_pair(p.first,p.first)
		:make_pair(p.second,p.second);
}
pair<Point,Point>crosspoint(const Circle&a,const Circle&b){
	double d=distance(a.o,b.o);
	double alpha=acos((a.r*a.r+d*d-b.r*b.r)/(2*a.r*d));
	double theta=arg(b.o-a.o);
	return minmax(a.o+polar(a.r,theta+alpha),a.o+polar(a.r,theta-alpha));
}
pair<Point,Point>tangent(const Circle&c,const Point&p){
	return crosspoint(c,Circle(p,sqrt(norm(c.o-p)-c.r*c.r)));
}
vector<Line>tangent(const Circle&a,const Circle&b){
	vector<Line>ret;
	double g=distance(a.o,b.o);
	if(eq(g,0))return ret;
	Point u=(b.o-a.o)/g;
	Point v=rotate(u,M_PI/2);
	for(int s:{-1,1}){
		double h=(a.r+b.r*s)/g;
		if(eq(h,0))ret.emplace_back(a.o+u*a.r,a.o+u*a.r+v);
		else if(1-h*h>0){
			Point U=u*h,V=v*sqrt(1-h*h);
			ret.emplace_back(a.o+(U+V)*a.r,b.o-(U+V)*b.r*s);
			ret.emplace_back(a.o+(U-V)*a.r,b.o-(U-V)*b.r*s);
		}
	}
	return ret;
}
bool is_convex(const Polygon&P){
	for(int i=0;i<P.size();i++)
		if(ccw(P[i],P[(i+1)%P.size()],P[(i+2)%P.size()])==CLOCKWISE)return false;
	return true;
}
Polygon convex_full(Polygon P,bool ONSEG){
	if(P.size()<=2)return P;
	sort(P.begin(),P.end());
	Polygon ret(2*P.size());
	int k=0,t;
	if(ONSEG){
		for(const Point&p:P){
			while(k>=2&&ccw(ret[k-2],ret[k-1],p)==CLOCKWISE)k--;
			ret[k++]=p;
		}
		t=k;
		for(int i=P.size()-2;i>=0;i--){
			while(k>=t+1&&ccw(ret[k-2],ret[k-1],P[i])==CLOCKWISE)k--;
			ret[k++]=P[i];
		}
	}
	else{
		for(const Point&p:P){
			while(k>=2&&ccw(ret[k-2],ret[k-1],p)!=COUNTER_CLOCKWISE)k--;
			ret[k++]=p;
		}
		t=k;
		for(int i=P.size()-2;i>=0;i--){
			while(k>=t+1&&ccw(ret[k-2],ret[k-1],P[i])!=COUNTER_CLOCKWISE)k--;
			ret[k++]=P[i];
		}
	}
	ret.resize(k-1);
	int mi=0;
	for(int i=1;i<k-1;i++)
		if(eq(ret[mi].y,ret[i].y)?ret[mi].x>ret[i].x:ret[mi].y>ret[i].y)mi=i;
	rotate(ret.begin(),ret.begin()+mi,ret.end());
	return ret;
}
int contain(const Polygon&P,const Point&p){
	bool in=false;
	for(int i=0;i<P.size();i++){
		Segment s(P[i],P[(i+1)%P.size()]);
		if(intersect(s,p))return ON;
		else{
			Point a=s.p1-p,b=s.p2-p;
			if(a.y>b.y)swap(a,b);
			if(a.y<EPS&&EPS<b.y&&cross(a,b)>EPS)in=!in;
		}
	}
	return in?IN:OUT;
}
int contain(const Circle&c,const Point&p){
	double d=distance(c.o,p);
	return eq(d,c.r)?ON:d<c.r?IN:OUT;
}
Polygon convex_cut(const Polygon&P,const Line&s){
	Polygon ret;
	for(int i=0;i<P.size();i++){
		Segment t(P[i],P[(i+1)%P.size()]);
		if(ccw(s,t.p1)!=CLOCKWISE)ret.push_back(t.p1);
		if(!parallel(s,t)&&!intersect(s,t.p1)
			&&!intersect(s,t.p2)&&intersect(s,t))ret.push_back(crosspoint(s,t));
	}
	return ret;
}
double area(const Polygon&P){
	double ret=0;
	for(int i=0;i<P.size();i++)ret+=cross(P[i],P[(i+1)%P.size()]);
	return ret/2;
}
double area(const Polygon&P,const Line&s){return area(convex_cut(P,s));}
double area(const Polygon&P,const Circle&c){}
int main(){
	int n;
	Polygon P;
	for(cin>>n;n--;)
	{
		Point p;cin>>p;P.push_back(p);
	}
	cin>>n;
	for(;n--;)
	{
		Line a;cin>>a.p1>>a.p2;
		cout<<fixed<<setprecision(9)<<area(P,a)<<endl;
	}
}