#include <cstdio>

 #include <cstring>

 #include <iostream>

 #include <algorithm>

 #include <vector>

 #include <cmath>

 using namespace std;

 struct Point {

     double x, y;

     Point() {}

     Point(double x, double y) : x(x), y(y) {}

 } ;

 template<class T> T sqr(T x) { return x * x;}

 typedef Point Vec;

 Vec operator + (Vec a, Vec b) { return Vec(a.x + b.x, a.y + b.y);}

 Vec operator - (Vec a, Vec b) { return Vec(a.x - b.x, a.y - b.y);}

 Vec operator * (Vec a, double p) { return Vec(a.x * p, a.y * p);}

 Vec operator / (Vec a, double p) { return Vec(a.x / p, a.y / p);}

 const double EPS = 1e-;

 const double PI = acos(-1.0);

 inline int sgn(double x) { return (x > EPS) - (x < -EPS);}

 inline double dotDet(Vec a, Vec b) { return a.x * b.x + a.y * b.y;}

 inline double crossDet(Vec a, Vec b) { return a.x * b.y - a.y * b.x;}

 inline double dotDet(Point o, Point a, Point b) { return dotDet(a - o, b - o);}

 inline double crossDet(Point o, Point a, Point b) { return crossDet(a - o, b - o);}

 inline double vecLen(Vec x) { return sqrt(dotDet(x, x));}

 inline double toRad(double deg) { return deg / 180.0 * PI;}

 inline double angle(Vec v) { return atan2(v.y, v.x);}

 inline Vec vecUnit(Vec x) { return x / vecLen(x);}

 inline Vec normal(Vec x) { return Vec(-x.y, x.x) / vecLen(x);}

 const int N = ;

 struct DLine {

     Point p;

     Vec v;

     double ang;

     DLine() {}

     DLine(Point p, Vec v) : p(p), v(v) { ang = atan2(v.y, v.x);}

     bool operator < (DLine L) const { return ang < L.ang;}

 } dl[N];

 inline bool onLeft(DLine L, Point p) { return crossDet(L.v, p - L.p) > ;}

 Point dLineIntersect(DLine a, DLine b) {

     Vec u = a.p - b.p;

     double t = crossDet(b.v, u) / crossDet(a.v, b.v);

     return a.p + a.v * t;

 }

 struct Poly {

     vector<Point> pt;

     Poly() { pt.clear();}

     ~Poly() {}

     Poly(vector<Point> &pt) : pt(pt) {}

     Point operator [] (int x) { return pt[x];}

     int size() { return pt.size();}

     double area() {

         double ret = 0.0;

         int sz = pt.size();

         pt.push_back(pt[]);

         for (int i = ; i <= sz; i++) ret += crossDet(pt[i], pt[i - ]);

         pt.pop_back();

         return fabs(ret / 2.0);

     }

 } ;

 Poly halfPlane(DLine *L, int n) {

     Poly ret = Poly();

     sort(L, L + n);

     int fi, la;

     Point *p = new Point[n];

     DLine *q = new DLine[n];

     q[fi = la = ] = L[];

     for (int i = ; i < n; i++) {

         while (fi < la && !onLeft(L[i], p[la - ])) la--;

         while (fi < la && !onLeft(L[i], p[fi])) fi++;

         q[++la] = L[i];

         if (sgn(crossDet(q[la].v, q[la - ].v)) == ) {

             la--;

             if (onLeft(q[la], L[i].p)) q[la] = L[i];

         }

         if (fi < la) p[la - ] = dLineIntersect(q[la - ], q[la]);

     }

     while (fi < la && !onLeft(q[fi], p[la - ])) la--;

     if (la < fi) return ret;

     p[la] = dLineIntersect(q[la], q[fi]);

     for (int i = fi; i <= la; i++) ret.pt.push_back(p[i]);

     return ret;

 }

 const int dir[][] = { {, }, {, }, {, }, {, }};

 int main() {

     int T, n;

     while (~scanf("%d", &n)) {

         Point x[];

         for (int i = ; i < n; i++) {

             for (int j = ; j < ; j++) {

                 scanf("%lf%lf", &x[j].x, &x[j].y);

             }

             dl[i] = DLine(x[], x[] - x[]);

         }

         for (int i = ; i < ; i++) {

             dl[n + i] = DLine(Point(10000.0 * dir[i][], 10000.0 * dir[i][]),

                               Point(10000.0 * dir[(i + ) & ][], 10000.0 * dir[(i + ) & ][]) - Point(10000.0 * dir[i][], 10000.0 * dir[i][]));

         }

         Poly tmp = halfPlane(dl, n + );

         printf("%.1f\n", tmp.area());

     }

     return ;

 }