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:
#include<bits/stdc++.h>
#define EPS (1e-10)
#define equals(a,b) (fabs((a)-(b)) < EPS)
#define PI 3.141592653589793238
#define int long long
 
using namespace std;

static const int COUNTER_CLOCKWISE = 1;
static const int CLOCKWISE = -1;
static const int ONLINE_BACK = 2;
static const int ONLINE_FRONT = -2;
static const int ON_SEGMENT = 0;

struct Point{
  double x,y;
  Point(){}
  Point(double x,double y) :x(x),y(y){}
  Point operator + (Point p) {return Point(x+p.x,y+p.y);}
  Point operator - (Point p) {return Point(x-p.x,y-p.y);}
  Point operator * (double k) {return Point(x*k,y*k);}
  Point operator / (double k) {return Point(x/k,y/k);}
  double norm(){return x*x+y*y;}
  double abs(){return sqrt(norm());}

  bool operator < (const Point &p) const{
    return x!=p.x ? x < p.x : y < p.y;
  }

  bool operator == (const Point &p) const{
    return fabs(x-p.x) < EPS && fabs(y-p.y) < EPS;
  }
};

istream &operator >> (istream &is,Point &p){
  is>>p.x>>p.y;
  return is;
}

ostream &operator << (ostream &os,Point p){
  os<<fixed<<setprecision(12)<<p.x<<" "<<p.y;
  return os;
}

typedef Point Vector;
typedef vector<Point> Polygon;

struct Segment{
  Point p1,p2;
  Segment(){}
  Segment(Point p1, Point p2):p1(p1),p2(p2){}
};
typedef Segment Line;

struct Circle{
  Point c;
  double r;
  Circle(){}
  Circle(Point c,double r):c(c),r(r){}
};

double norm(Vector a){
  return a.x*a.x+a.y*a.y;
}
double abs(Vector a){
  return sqrt(norm(a));
}
double dot(Vector a,Vector b){
  return a.x*b.x+a.y*b.y;
}
double cross(Vector a,Vector b){
  return a.x*b.y-a.y*b.x;
}

bool isOrthogonal(Vector a,Vector b){
  return equals(dot(a,b),0.0);
}

bool isOrthogonal(Point a1,Point a2,Point b1,Point b2){
  return isOrthogonal(a1-a2,b1-b2);
}

bool isOrthogonal(Segment s1,Segment s2){
  return equals(dot(s1.p2-s1.p1,s2.p2-s2.p1),0.0);
}

bool isParallel(Vector a,Vector b){
  return equals(cross(a,b),0.0);
}

bool isParallel(Point a1,Point a2,Point b1,Point b2){
  return isParallel(a1-a2,b1-b2);
}

bool isParallel(Segment s1,Segment s2){
  return equals(cross(s1.p2-s1.p1,s2.p2-s2.p1),0.0); 
}

Point project(Segment s,Point p){
  Vector base=s.p2-s.p1;
  double r=dot(p-s.p1,base)/norm(base);
  return s.p1+base*r;
}

Point reflect(Segment s,Point p){
  return p+(project(s,p)-p)*2.0;
}

int ccw(Point p0,Point p1,Point p2){
  Vector a = p1-p0;
  Vector b = p2-p0;
  if(cross(a,b) > EPS) return COUNTER_CLOCKWISE;
  if(cross(a,b) < -EPS) return CLOCKWISE;
  if(dot(a,b) < -EPS) return ONLINE_BACK;
  if(a.norm()<b.norm()) return ONLINE_FRONT;
  return ON_SEGMENT;
}

bool intersect(Point p1,Point p2,Point p3,Point p4){
  return (ccw(p1,p2,p3)*ccw(p1,p2,p4) <= 0 &&
	  ccw(p3,p4,p1)*ccw(p3,p4,p2) <= 0 );
}

bool intersect(Segment s1,Segment s2){
  return intersect(s1.p1,s1.p2,s2.p1,s2.p2);
}

double getDistanceLP(Line l,Point p){
  return abs(cross(l.p2-l.p1,p-l.p1)/abs(l.p2-l.p1));
}

double getDistanceSP(Segment s,Point p){
  if(dot(s.p2-s.p1,p-s.p1) < 0.0 ) return abs(p-s.p1);
  if(dot(s.p1-s.p2,p-s.p2) < 0.0 ) return abs(p-s.p2);
  return getDistanceLP(s,p);
}

double getDistance(Segment s1,Segment s2){
  if(intersect(s1,s2)) return 0.0;
  return min(min(getDistanceSP(s1,s2.p1),getDistanceSP(s1,s2.p2)),
	     min(getDistanceSP(s2,s1.p1),getDistanceSP(s2,s1.p2)));
}

Point getCrossPoint(Segment s1,Segment s2){
  Vector base=s2.p2-s2.p1;
  double d1=abs(cross(base,s1.p1-s2.p1));
  double d2=abs(cross(base,s1.p2-s2.p1));
  double t=d1/(d1+d2);
  return s1.p1+(s1.p2-s1.p1)*t;
}


pair<Point,Point> getCrossPoints(Circle c,Line l){
  Vector pr=project(l,c.c);
  Vector e=(l.p2-l.p1)/abs(l.p2-l.p1);
  double base=sqrt(c.r*c.r-norm(pr-c.c));
  return make_pair(pr+e*base,pr-e*base);
}


double arg(Vector p){
  return atan2(p.y,p.x);
}

Vector polar(double a,double r){
  return Point(cos(r)*a,sin(r)*a);
}

pair<Point,Point> getCrossPoints(Circle c1,Circle c2){
  double d=abs(c1.c-c2.c);
  double a=acos((c1.r*c1.r+d*d-c2.r*c2.r)/(2*c1.r*d));
  double t=arg(c2.c-c1.c);
  return make_pair(c1.c+polar(c1.r,t+a),c1.c+polar(c1.r,t-a));
}

int contains(Polygon g,Point p){
  int n=g.size();
  bool x=false;
  for(int i=0;i<n;i++){
    Point a=g[i]-p,b=g[(i+1)%n]-p;
    if(fabs(cross(a,b)) < EPS && dot(a,b) < EPS) return 1;
    if(a.y>b.y) swap(a,b);
    if(a.y < EPS && EPS < b.y && cross(a,b) > EPS ) x = !x;
  }
  return (x?2:0);
}

Polygon andrewScan(Polygon s){
  Polygon u,l;
  if(s.size()<3) return s;
  sort(s.begin(),s.end());
  u.push_back(s[0]);
  u.push_back(s[1]);
  l.push_back(s[s.size()-1]);
  l.push_back(s[s.size()-2]);
  for(int i=2;i<(int)s.size();i++){
    for(int n=u.size();n>=2&&ccw(u[n-2],u[n-1],s[i])!=CLOCKWISE;n--){
      u.pop_back();
    }
    u.push_back(s[i]);
  } 
  for(int i=s.size()-3;i>=0;i--){
    for(int n=l.size();n>=2&&ccw(l[n-2],l[n-1],s[i])!=CLOCKWISE;n--){
      l.pop_back();
    }
    l.push_back(s[i]);
  }
  reverse(l.begin(),l.end());
  for(int i=u.size()-2;i>=1;i--) l.push_back(u[i]);
  return l;
} 

bool isConvex(Polygon p){
  bool f=1;
  int n=p.size();
  for(int i=0;i<n;i++){
    int t=ccw(p[(i+n-1)%n],p[i],p[(i+1)%n]);
    f&=t!=CLOCKWISE;
  }
  return f;
}

double area(Polygon s){
  double res=0;
  for(int i=0;i<(int)s.size();i++){
    res+=cross(s[i],s[(i+1)%s.size()])/2.0;
  }
  return abs(res);
}


Point getCrossPointLL(Line l1,Line l2){
  double a=cross(l1.p2-l1.p1,l2.p2-l2.p1);
  double b=cross(l1.p2-l1.p1,l1.p2-l2.p1);
  if(abs(a)<EPS&&abs(b)<EPS) return l2.p1;
  return l2.p1+(l2.p2-l2.p1)*(b/a);
}

Polygon convexCut(Polygon p,Line l){
  Polygon q;
  for(int i=0;i<(int)p.size();i++){
    Point a=p[i],b=p[(i+1)%p.size()];
    if(ccw(l.p1,l.p2,a)!=-1) q.push_back(a);
    if(ccw(l.p1,l.p2,a)*ccw(l.p1,l.p2,b)<0)
      q.push_back(getCrossPointLL(Line(a,b),l));
  }
  return q;
}

Line bisector(Point p1,Point p2){
  Circle c1=Circle(p1,abs(p1-p2)),c2=Circle(p2,abs(p1-p2));
  pair<Point,Point> p=getCrossPoints(c1,c2);
  if(cross(p2-p1,p.first-p1)>0) swap(p.first,p.second);
  return Line(p.first,p.second);
}


Vector translate(Vector v,double theta){
  Vector res;
  res.x=cos(theta)*v.x-sin(theta)*v.y;
  res.y=sin(theta)*v.x+cos(theta)*v.y;
  return res;
}

vector<Line> corner(Line l1,Line l2){
  vector<Line> res;
  if(isParallel(l1,l2)){
    double d=getDistanceLP(l1,l2.p1)/2.0;
    Vector v1=l1.p2-l1.p1;
    v1=v1/v1.abs()*d;
    Point p=l2.p1+translate(v1,90.0*(PI/180.0));
    double d1=getDistanceLP(l1,p);
    double d2=getDistanceLP(l2,p);
    if(abs(d1-d2)>d){
      p=l2.p1+translate(v1,-90.0*(PI/180.0));
    }
    res.push_back(Line(p,p+v1));
  }else{
    Point p=getCrossPointLL(l1,l2);
    Vector v1=l1.p2-l1.p1,v2=l2.p2-l2.p1;
    v1=v1/v1.abs();
    v2=v2/v2.abs();
    res.push_back(Line(p,p+(v1+v2)));
    res.push_back(Line(p,p+translate(v1+v2,90.0*(PI/180.0))));
  }
  return res;
}

bool sort_y(Point a,Point b){
  return a.y!=b.y ? a.y < b.y : a.x < b.x;
}

Polygon convex_hull(Polygon ps){
  int n=ps.size();
  sort(ps.begin(),ps.end(),sort_y);
  int k=0;
  Polygon qs(n*2);
  for(int i=0;i<n;i++){
    while(k>1&&cross(qs[k-1]-qs[k-2],ps[i]-qs[k-1])<0) k--;
    qs[k++]=ps[i];
  }
  for(int i=n-2,t=k;i>=0;i--){
    while(k>t&&cross(qs[k-1]-qs[k-2],ps[i]-qs[k-1])<0) k--;
    qs[k++]=ps[i];
  }
  qs.resize(k-1);
  return qs;
}

double diameter(Polygon s){
  Polygon p=s;
  int n=p.size();
  if(n==2) return abs(p[0]-p[1]);
  int i=0,j=0;
  for(int k=0;k<n;k++){
    if(p[i]<p[k]) i=k;
    if(!(p[j]<p[k])) j=k;
  }
  double res=0;
  int si=i,sj=j;
  while(i!=sj||j!=si){
    res=max(res,abs(p[i]-p[j]));
    if(cross(p[(i+1)%n]-p[i],p[(j+1)%n]-p[j])<0.0){
      i=(i+1)%n;
    }else{
      j=(j+1)%n;
    }
  }
  return res;
}

signed main(){
  int n;
  cin>>n;
  Polygon g(n);
  for(int i=0;i<n;i++) cin>>g[i];
  Polygon p=andrewScan(g);
  int q;
  cin>>q;
  while(q--){
    Line l;
    cin>>l.p1>>l.p2;
    printf("%.12f\n",area(convexCut(p,l)));
  }
  return 0;
}