Problem: The night after the graduation ceremony graduate students of German University in Cairo (GUC) are playing darts. As there's no real dart board available, the photographs of members of the GUC upper management are being used.

So, n rectangular photos are placed on the wall. They can overlap arbitrary and even coincide. The photos are not necessarily placed horizontally or vertically, they could also be rotated before being pinned to the wall.

The score of one dart throw is simply the number of photos the dart went through.

Fatma has made a throw but her score was not recorded. She only remembers that she did make it into at least one photo.

Assuming that the probability distribution of the throw is equal across the whole wall, what would be the expectation of Fatma's score?

Input

The first line of input contains integer n (1 ≤ n ≤ 500) — the number of photos on the wall. Then follow n lines describing the photos, each containing 8 single-space-separated integers (coordinates of 4 vertices): x1, y1, x2, y2, x3, y3, x4, y4. Each photo is a rectangle with a nonzero area. The coordinates are integers, not exceeding 104 by absolute value. The coordinates of the rectangle are given in either clockwise or counterclockwise order.

Output

Print the expected score of the throw. The answer will be accepted if it has absolute or relative error not exceeding 10 - 6.

Examples

Input

1
0 0 0 2 2 2 2 0


Output

1.0000000000


Input

1
-1 0 0 1 1 0 0 -1


Output

1.0000000000


Input

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


Output

1.5000000000


Input

2
-1 0 0 1 1 0 0 -1
0 0 1 1 2 0 1 -1


Output

1.1428571429

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:36777216")
using namespace std;
string __file__() {
  string res = "<stdin>";
  int r = int((res).size()) - 1;
  while (res[r] != '.') --r;
  int l = r - 1;
  while (res[l] != '\\') --l;
  ++l;
  return res.substr(l, r - l);
}
void Exec(string a, string b, string c) {
  if (b.empty()) b = __file__();
  string cmd = a + ' ' + b + '.' + c;
  system(cmd.c_str());
}
void Ruby(string file = "") { Exec("ruby", file, "rb"); }
void Python(string file = "") { Exec("python", file, "py"); }
void Haskell(string file = "") { Exec("runghc", file, "hs"); }
void Pascal(string file = "") { Exec("pascal", file, "pas"); }
void Ocaml(string file = "") { Exec("ocaml", file, "ml"); }
template <class T>
inline T &RD(T &);
template <class T>
inline void OT(const T &);
inline long long RD() {
  long long x;
  return RD(x);
}
inline double &RF(double &);
inline double RF() {
  double x;
  return RF(x);
}
inline char *RS(char *s);
inline char &RC(char &c);
inline char RC();
inline char &RC(char &c) {
  scanf(" %c", &c);
  return c;
}
inline char RC() {
  char c;
  return RC(c);
}
template <class T>
inline T &RDD(T &x) {
  char c;
  for (c = getchar(); c < '-'; c = getchar())
    ;
  if (c == '-') {
    x = '0' - getchar();
    for (c = getchar(); '0' <= c && c <= '9'; c = getchar())
      x = x * 10 + '0' - c;
  } else {
    x = c - '0';
    for (c = getchar(); '0' <= c && c <= '9'; c = getchar())
      x = x * 10 + c - '0';
  }
  return x;
}
inline long long RDD() {
  long long x;
  return RDD(x);
}
template <class T0, class T1>
inline T0 &RD(T0 &x0, T1 &x1) {
  RD(x0), RD(x1);
  return x0;
}
template <class T0, class T1, class T2>
inline T0 &RD(T0 &x0, T1 &x1, T2 &x2) {
  RD(x0), RD(x1), RD(x2);
  return x0;
}
template <class T0, class T1, class T2, class T3>
inline T0 &RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3) {
  RD(x0), RD(x1), RD(x2), RD(x3);
  return x0;
}
template <class T0, class T1, class T2, class T3, class T4>
inline T0 &RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4) {
  RD(x0), RD(x1), RD(x2), RD(x3), RD(x4);
  return x0;
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline T0 &RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5) {
  RD(x0), RD(x1), RD(x2), RD(x3), RD(x4), RD(x5);
  return x0;
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline T0 &RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5, T6 &x6) {
  RD(x0), RD(x1), RD(x2), RD(x3), RD(x4), RD(x5), RD(x6);
  return x0;
}
template <class T0, class T1>
inline void OT(const T0 &x0, const T1 &x1) {
  OT(x0), OT(x1);
}
template <class T0, class T1, class T2>
inline void OT(const T0 &x0, const T1 &x1, const T2 &x2) {
  OT(x0), OT(x1), OT(x2);
}
template <class T0, class T1, class T2, class T3>
inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3) {
  OT(x0), OT(x1), OT(x2), OT(x3);
}
template <class T0, class T1, class T2, class T3, class T4>
inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3,
               const T4 &x4) {
  OT(x0), OT(x1), OT(x2), OT(x3), OT(x4);
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3,
               const T4 &x4, const T5 &x5) {
  OT(x0), OT(x1), OT(x2), OT(x3), OT(x4), OT(x5);
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3,
               const T4 &x4, const T5 &x5, const T6 &x6) {
  OT(x0), OT(x1), OT(x2), OT(x3), OT(x4), OT(x5), OT(x6);
}
inline char &RC(char &a, char &b) {
  RC(a), RC(b);
  return a;
}
inline char &RC(char &a, char &b, char &c) {
  RC(a), RC(b), RC(c);
  return a;
}
inline char &RC(char &a, char &b, char &c, char &d) {
  RC(a), RC(b), RC(c), RC(d);
  return a;
}
inline char &RC(char &a, char &b, char &c, char &d, char &e) {
  RC(a), RC(b), RC(c), RC(d), RC(e);
  return a;
}
inline char &RC(char &a, char &b, char &c, char &d, char &e, char &f) {
  RC(a), RC(b), RC(c), RC(d), RC(e), RC(f);
  return a;
}
inline char &RC(char &a, char &b, char &c, char &d, char &e, char &f, char &g) {
  RC(a), RC(b), RC(c), RC(d), RC(e), RC(f), RC(g);
  return a;
}
inline double &RF(double &a, double &b) {
  RF(a), RF(b);
  return a;
}
inline double &RF(double &a, double &b, double &c) {
  RF(a), RF(b), RF(c);
  return a;
}
inline double &RF(double &a, double &b, double &c, double &d) {
  RF(a), RF(b), RF(c), RF(d);
  return a;
}
inline double &RF(double &a, double &b, double &c, double &d, double &e) {
  RF(a), RF(b), RF(c), RF(d), RF(e);
  return a;
}
inline double &RF(double &a, double &b, double &c, double &d, double &e,
                  double &f) {
  RF(a), RF(b), RF(c), RF(d), RF(e), RF(f);
  return a;
}
inline double &RF(double &a, double &b, double &c, double &d, double &e,
                  double &f, double &g) {
  RF(a), RF(b), RF(c), RF(d), RF(e), RF(f), RF(g);
  return a;
}
inline void RS(char *s1, char *s2) { RS(s1), RS(s2); }
inline void RS(char *s1, char *s2, char *s3) { RS(s1), RS(s2), RS(s3); }
template <class T0, class T1>
inline void RDD(T0 &a, T1 &b) {
  RDD(a), RDD(b);
}
template <class T0, class T1, class T2>
inline void RDD(T0 &a, T1 &b, T2 &c) {
  RDD(a), RDD(b), RDD(c);
}
template <class T>
inline void RST(T &A) {
  memset(A, 0, sizeof(A));
}
template <class T>
inline void FLC(T &A, int x) {
  memset(A, x, sizeof(A));
}
template <class T>
inline void CLR(T &A) {
  A.clear();
}
template <class T0, class T1>
inline void RST(T0 &A0, T1 &A1) {
  RST(A0), RST(A1);
}
template <class T0, class T1, class T2>
inline void RST(T0 &A0, T1 &A1, T2 &A2) {
  RST(A0), RST(A1), RST(A2);
}
template <class T0, class T1, class T2, class T3>
inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3) {
  RST(A0), RST(A1), RST(A2), RST(A3);
}
template <class T0, class T1, class T2, class T3, class T4>
inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4) {
  RST(A0), RST(A1), RST(A2), RST(A3), RST(A4);
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5) {
  RST(A0), RST(A1), RST(A2), RST(A3), RST(A4), RST(A5);
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6) {
  RST(A0), RST(A1), RST(A2), RST(A3), RST(A4), RST(A5), RST(A6);
}
template <class T0, class T1>
inline void FLC(T0 &A0, T1 &A1, int x) {
  FLC(A0, x), FLC(A1, x);
}
template <class T0, class T1, class T2>
inline void FLC(T0 &A0, T1 &A1, T2 &A2, int x) {
  FLC(A0, x), FLC(A1, x), FLC(A2, x);
}
template <class T0, class T1, class T2, class T3>
inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, int x) {
  FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x);
}
template <class T0, class T1, class T2, class T3, class T4>
inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, int x) {
  FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x), FLC(A4, x);
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, int x) {
  FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x), FLC(A4, x), FLC(A5, x);
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6, int x) {
  FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x), FLC(A4, x), FLC(A5, x),
      FLC(A6, x);
}
template <class T>
inline void CLR(priority_queue<T, vector<T>, less<T> > &Q) {
  while (!Q.empty()) Q.pop();
}
template <class T>
inline void CLR(priority_queue<T, vector<T>, greater<T> > &Q) {
  while (!Q.empty()) Q.pop();
}
template <class T>
inline void CLR(stack<T> &S) {
  while (!S.empty()) S.pop();
}
template <class T0, class T1>
inline void CLR(T0 &A0, T1 &A1) {
  CLR(A0), CLR(A1);
}
template <class T0, class T1, class T2>
inline void CLR(T0 &A0, T1 &A1, T2 &A2) {
  CLR(A0), CLR(A1), CLR(A2);
}
template <class T0, class T1, class T2, class T3>
inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3) {
  CLR(A0), CLR(A1), CLR(A2), CLR(A3);
}
template <class T0, class T1, class T2, class T3, class T4>
inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4) {
  CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4);
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5) {
  CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4), CLR(A5);
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6) {
  CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4), CLR(A5), CLR(A6);
}
template <class T>
inline void CLR(T &A, int n) {
  for (int i = 0; i < int(n); ++i) CLR(A[i]);
}
template <class T>
inline bool EPT(T &a) {
  return a.empty();
}
template <class T>
inline T &SRT(T &A) {
  sort(A.begin(), A.end());
  return A;
}
template <class T>
inline T &RVS(T &A) {
  reverse(A.begin(), A.end());
  return A;
}
template <class T>
inline T &UNQ(T &A) {
  A.resize(unique(SRT(A).begin(), SRT(A).end()) - A.begin());
  return A;
}
template <class T, class C>
inline T &SRT(T &A, C B) {
  sort(A.begin(), A.end(), B);
  return A;
}
const int MOD = int(1e9) + 7;
const int INF = 0x3f3f3f3f;
const long long INFF = 0x3f3f3f3f3f3f3f3fLL;
const double EPS = 1e-9;
const double OO = 1e20;
const double PI = acos(-1.0);
const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};
template <class T>
inline void checkMin(T &a, const T b) {
  if (b < a) a = b;
}
template <class T>
inline void checkMax(T &a, const T b) {
  if (a < b) a = b;
}
template <class T>
inline void checkMin(T &a, T &b, const T x) {
  checkMin(a, x), checkMin(b, x);
}
template <class T>
inline void checkMax(T &a, T &b, const T x) {
  checkMax(a, x), checkMax(b, x);
}
template <class T, class C>
inline void checkMin(T &a, const T b, C c) {
  if (c(b, a)) a = b;
}
template <class T, class C>
inline void checkMax(T &a, const T b, C c) {
  if (c(a, b)) a = b;
}
template <class T>
inline T min(T a, T b, T c) {
  return min(min(a, b), c);
}
template <class T>
inline T max(T a, T b, T c) {
  return max(max(a, b), c);
}
template <class T>
inline T min(T a, T b, T c, T d) {
  return min(min(a, b), min(c, d));
}
template <class T>
inline T max(T a, T b, T c, T d) {
  return max(max(a, b), max(c, d));
}
template <class T>
inline T sqr(T a) {
  return a * a;
}
template <class T>
inline T cub(T a) {
  return a * a * a;
}
template <class T>
inline T ceil(T x, T y) {
  return (x - 1) / y + 1;
}
inline int sgn(double x) { return x < -EPS ? -1 : x > EPS; }
inline int sgn(double x, double y) { return sgn(x - y); }
inline double cos(double a, double b, double c) {
  return (sqr(a) + sqr(b) - sqr(c)) / (2 * a * b);
}
inline double cot(double x) { return 1. / tan(x); };
inline double sec(double x) { return 1. / cos(x); };
inline double csc(double x) { return 1. / sin(x); };
namespace CG {
struct Po;
struct Line;
struct Seg;
struct Triangle;
struct Circle;
struct Po {
  double x, y;
  Po(double x = 0, double y = 0) : x(x), y(y) {}
  inline void input() { RF(x, y); }
  inline friend istream &operator>>(istream &in, Po &p) {
    return in >> p.x >> p.y;
  }
  inline friend ostream &operator<<(ostream &out, Po p) {
    return out << "(" << p.x << ", " << p.y << ")";
  }
  inline bool operator==(const Po &r) const {
    return !sgn(x - r.x) && !sgn(y - r.y);
  };
  inline bool operator!=(const Po &r) const {
    return sgn(x - r.x) || sgn(y - r.y);
  }
  inline bool operator<(const Po &r) const {
    return sgn(x, r.x) < 0 || (!sgn(x, r.x) && sgn(y, r.y) < 0);
  }
  inline bool operator<=(const Po &r) const { return *this < r || *this == r; }
  inline bool operator>(const Po &r) const { return !(*this <= r); }
  inline bool operator>=(const Po &r) const { return !(*this < r); }
  inline Po operator-() const { return Po(-x, -y); }
  inline Po &operator+=(const Po &r) {
    x += r.x, y += r.y;
    return *this;
  }
  inline Po &operator-=(const Po &r) {
    x -= r.x, y -= r.y;
    return *this;
  }
  inline Po &operator*=(double k) {
    x *= k, y *= k;
    return *this;
  }
  inline Po &operator/=(double k) {
    x /= k, y /= k;
    return *this;
  }
  inline Po operator+(const Po &r) const { return Po(x + r.x, y + r.y); }
  inline Po operator-(const Po &r) const { return Po(x - r.x, y - r.y); }
  inline Po operator*(double k) const { return Po(x * k, y * k); }
  inline Po operator/(double k) const { return Po(x / k, y / k); }
  inline double operator*(const Po &) const;
  inline double operator^(const Po &) const;
  inline Po operator*(const Line &) const;
  inline double length2() const { return sqr(x) + sqr(y); }
  inline double length() const { return sqrt(length2()); }
  inline Po unit() const { return *this / length(); }
  inline bool dgt() const { return !sgn(x) && !sgn(y); }
  inline double atan() const { return atan2(y, x); }
  inline Po lt90() {
    sym(), x = -x;
    return *this;
  }
  inline Po rt90() {
    sym(), y = -y;
    return *this;
  }
  inline Po sym() {
    swap(x, y);
    return *this;
  }
  inline Po symm() {
    x = -x, y = -y;
    return *this;
  }
  inline Po rotate(double a, const Po &o = Po()) {
    x -= o.x, y -= o.y;
    return *this = Po(x * cos(a) - y * sin(a), y * cos(a) + x * sin(a)) + o;
  }
  inline Po symmetry(const Line &);
};
inline Po sym(Po p) {
  p.sym();
  return p;
}
inline Po symm(Po p) {
  p.symm();
  return p;
}
inline Po lt90(Po p) {
  p.lt90();
  return p;
}
inline Po rt90(Po p) {
  p.rt90();
  return p;
}
inline Po rotate(Po p, double alpha, const Po &o = Po()) {
  return p.rotate(alpha, o);
}
inline Po operator*(double k, Po a) { return a * k; }
inline double dot(const double &x1, const double &y1, const double &x2,
                  const double &y2) {
  return x1 * x2 + y1 * y2;
}
inline double dot(const Po &a, const Po &b) { return dot(a.x, a.y, b.x, b.y); }
inline double dot(const Po &p0, const Po &p1, const Po &p2) {
  return dot(p1 - p0, p2 - p0);
}
inline double det(const double &x1, const double &y1, const double &x2,
                  const double &y2) {
  return x1 * y2 - x2 * y1;
}
inline double det(const Po &a, const Po &b) { return det(a.x, a.y, b.x, b.y); }
inline double det(const Po &p0, const Po &p1, const Po &p2) {
  return det(p1 - p0, p2 - p0);
}
template <class T1, class T2>
inline int dett(const T1 &x, const T2 &y) {
  return sgn(det(x, y));
}
template <class T1, class T2>
inline int dott(const T1 &x, const T2 &y) {
  return sgn(dot(x, y));
}
template <class T1, class T2, class T3>
inline int dett(const T1 &x, const T2 &y, const T3 &z) {
  return sgn(det(x, y, z));
}
template <class T1, class T2, class T3>
inline int dott(const T1 &x, const T2 &y, const T3 &z) {
  return sgn(dot(x, y, z));
}
template <class T1, class T2, class T3, class T4>
inline int dett(const T1 &x, const T2 &y, const T3 &z, const T4 &w) {
  return sgn(det(x, y, z, w));
}
template <class T1, class T2, class T3, class T4>
inline int dott(const T1 &x, const T2 &y, const T3 &z, const T4 &w) {
  return sgn(dot(x, y, z, w));
}
inline double dist2(const double &x, const double &y) {
  return sqr(x) + sqr(y);
}
inline double dist2(const double &x, const double &y, const double &z) {
  return sqr(x) + sqr(y) + sqr(z);
}
inline double dist2(const Po &a, const Po &b) {
  return dist2(a.x - b.x, a.y - b.y);
}
template <class T1, class T2>
inline double dist(const T1 &x, const T2 &y) {
  return sqrt(dist2(x, y));
}
template <class T1, class T2, class T3>
inline double dist(const T1 &x, const T2 &y, const T3 &z) {
  return sqrt(dist2(x, y, z));
}
double Po::operator*(const Po &r) const { return dot(*this, r); }
double Po::operator^(const Po &r) const { return det(*this, r); }
struct Line {
  Po a, b;
  Line(const Po &a = Po(), const Po &b = Po()) : a(a), b(b) {}
  Line(double x0, double y0, double x1, double y1)
      : a(Po(x0, y0)), b(Po(x1, y1)) {}
  Line(const Line &l) : a(l.a), b(l.b) {}
  Line(const Po &a, double alpha) : a(a), b(a + Po(cos(alpha), sin(alpha))) {}
  Line(double A, double B, double C) {
    C = -C;
    if (!::sgn(A))
      a = Po(0, C / B), b = Po(1, C / B);
    else if (!::sgn(B))
      a = Po(C / A, 0), b = Po(C / A, 1);
    else
      a = Po(0, C / B), b = Po(1, (C - A) / B);
  }
  void input() { a.input(), b.input(); }
  inline friend istream &operator>>(istream &in, Line &p) {
    return in >> p.a >> p.b;
  }
  inline friend ostream &operator<<(ostream &out, Line p) {
    return out << p.a << "-" << p.b;
  }
  inline Line operator+(const Po &x) const { return Line(a + x, b + x); }
  inline Line operator-(const Po &x) const { return Line(a - x, b - x); }
  inline Line operator*(double k) const { return Line(a * k, b * k); }
  inline Po operator*(const Line &) const;
  inline Po operator*(const Po &) const;
  inline double length2() const { return (b - a).length2(); }
  inline double length() const { return (b - a).length(); }
  inline bool dgt() const { return (b - a).dgt(); }
  inline int sgn(const Po &p) const { return dett(a, b, p); }
  inline int sgn(const Line &) const;
  inline bool same_sgn(const Po &p1, const Po &p2) const {
    return sgn(p1) == sgn(p2);
  }
  inline void getEquation(double &K, double &B) const {
    K = ::sgn(a.x, b.x) ? (b.y - a.y) / (b.x - a.x) : OO;
    B = a.y - K * a.x;
  }
  inline void getEquation(double &A, double &B, double &C) const {
    A = a.y - b.y, B = b.x - a.x, C = det(a, b);
  }
  inline void getIntersect(const Line &, Po &) const;
  inline Po foot(const Po &) const;
};
inline double dot(const Line &l1, const Line &l2) {
  return dot(l1.b - l1.a, l2.b - l2.a);
}
inline double det(const Line &l1, const Line &l2) {
  return det(l1.b - l1.a, l2.b - l2.a);
}
inline int Line::sgn(const Line &l) const { return dett(*this, l); }
inline Po intersect(const Line &l1, const Line &l2) {
  return l1.a + (l1.b - l1.a) * (det(l2.a, l1.a, l2.b) / det(l2, l1));
}
inline Po Line::operator*(const Line &l) const { return intersect(*this, l); }
inline Po Line::foot(const Po &p) const {
  return *this * Line(p, p + lt90(b - a));
}
inline Po Line::operator*(const Po &p) const { return *this * p; }
inline Po Po::operator*(const Line &l) const { return l * *this; }
inline void Line::getIntersect(const Line &l, Po &p) const { p = *this * l; }
inline Po Po::symmetry(const Line &l) {
  Po o = l * *this;
  return *this = o + o - *this;
}
inline Po symmetry(Po p, const Line &l) { return p.symmetry(l); }
struct Seg : public Line {
  Seg(const Po &a = Po(), const Po &b = Po()) : Line(a, b) {}
  Seg(double x0, double y0, double x1, double y1) : Line(x0, y0, x1, y1) {}
  Seg(const Line &l) : Line(l) {}
  Seg(const Po &a, double alpha) : Line(a, alpha) {}
  Seg(double A, double B, double C) : Line(A, B, C) {}
  inline int sgn(const Po &p) const;
  inline bool qrt(const Seg &l) const;
  inline int sgn(const Seg &l) const;
};
inline bool Seg::qrt(const Seg &l) const {
  return min(a.x, b.x) <= max(l.a.x, l.b.x) &&
         min(l.a.x, l.b.x) <= max(a.x, b.x) &&
         min(a.y, b.y) <= max(l.a.y, l.b.y) &&
         min(l.a.y, l.b.y) <= max(a.y, b.y);
}
inline int Seg::sgn(const Seg &l) const {
  if (!qrt(l)) return -1;
  int d1 = dett(a, b, l.a), d2 = dett(a, b, l.b), d3 = dett(l.a, l.b, a),
      d4 = dett(l.a, l.b, b);
  if ((d1 ^ d2) == -2 && (d3 ^ d4) == -2) return 1;
  return ((!d1 && dott(l.a - a, l.a - b) <= 0) ||
          (!d2 && dott(l.b - a, l.b - b) <= 0) ||
          (!d3 && dott(a - l.a, a - l.b) <= 0) ||
          (!d4 && dott(b - l.a, b - l.b) <= 0))
             ? 0
             : -1;
}
inline int Seg::sgn(const Po &p) const { return -dott(p, a, b); }
inline double dist2(const Line &l, const Po &p) {
  Po v0 = l.b - l.a, v1 = p - l.a;
  return sqr(fabs(det(v0, v1))) / v0.length2();
}
inline double dist2(const Line &l1, const Line &l2) {
  return dett(l1, l2) ? 0 : dist2(l1, l2.a);
}
inline double dist2(const Seg &l, const Po &p) {
  Po v0 = l.b - l.a, v1 = p - l.a, v2 = p - l.b;
  if (sgn(dot(v0, v1)) * sgn(dot(v0, v2)) <= 0)
    return dist2(Line(l), p);
  else
    return min(v1.length2(), v2.length2());
}
inline double dist2(const Seg &l1, const Line &l2) {
  Po v0 = l2.b - l2.a, v1 = l1.a - l2.a, v2 = l1.b - l2.a;
  double c1 = det(v0, v1), c2 = det(v0, v2);
  return sgn(c1) != sgn(c2) ? 0 : sqr(min(fabs(c1), fabs(c2))) / v0.length2();
}
inline double dist2(const Seg &l1, const Seg &l2) {
  if (l1.sgn(l2))
    return 0;
  else
    return min(dist2(l2, l1.a), dist2(l2, l1.b), dist2(l1, l2.a),
               dist2(l1, l2.b));
}
const int Disjoint = -2, Exscribe = -1, Cross = 0, Inscribe = 1, Contain = 2;
Po getX3(const Po &a, const Po &b, const Po &c) {
  Po v0 = b - a, v1 = c - a;
  double s0 = v0.length2(), s1 = v1.length2(), d = det(v0, v1);
  return Po(s0 * v1.y - s1 * v0.y, s1 * v0.x - s0 * v1.x) / d + a;
}
Po getX4(const Po &a, const Po &b, const Po &c) {
  return Line(a, Line(b, c) * a) * Line(b, Line(a, c) * b);
}
struct Circle {
  Po o;
  double r;
  Circle(const Po &o = Po(), double r = 0) : o(o), r(r) {}
  Circle(const Po &a, const Po &b) { o = (a + b) / 2, r = dist(a, b) / 2; }
  Circle(const Po &a, const Po &b, const Po &c) {
    o = getX3(a, b, c), r = dist(o, a);
  }
  void input() { RF(o.x, o.y, r); }
  void output() { printf("%.2f %.2f %.2f\n", o.x, o.y, r); }
  bool operator<(const Circle &c) const { return r < c.r; }
  inline int sgn(const Po &p) const { return ::sgn(sqr(r), dist2(o, p)); }
  inline int sgn(const Line &l) const { return ::sgn(sqr(r), dist2(l, o)); }
  inline int sgn(const Circle &c) const {
    double d = dist2(o, c.o);
    if (::sgn(sqr(r + c.r), d) < 0) return Disjoint;
    if (!::sgn(sqr(r + c.r), d)) return Exscribe;
    if (!::sgn(sqr(r - c.r), d)) return Inscribe;
    if (::sgn(sqr(r - c.r), d) > 0) return Contain;
    return Cross;
  }
  inline double s() { return PI * sqr(r); }
  inline double p() { return 2 * PI * r; }
  inline Po operator^(const Circle &c) const {
    return Po(det(Po(o.x, r), Po(c.o.x, c.r)),
              det(Po(o.y, r), Po(c.o.y, c.r))) /
           (c.r - r);
  }
  inline void getIntersect(const Line &l, Po &p0, Po &p1) const {
    Po m = l.foot(o), d = (l.b - l.a).unit() * sqrt(sqr(r) - dist2(l, o));
    p0 = m + d, p1 = m - d;
  }
  inline void getTangency(const Po &p, Po &p0, Po &p1) const {
    double d = dist(o, p), a = acos(r / d);
    Po op = (p - o).unit() * r;
    p0 = o + rotate(op, a), p1 = o + rotate(op, -a);
  }
  inline void getTangency(const Circle &c, Po &p0, Po &p1, Po &p2,
                          Po &p3) const {
    if (!::sgn(r, c.r)) {
      Po d = (o - c.o).rt90().unit() * r;
      p0 = o + d, p1 = o - d, p2 = c.o + d, p3 = c.o - d;
    } else {
      Po p = (*this) ^ c;
      getTangency(p, p0, p1), c.getTangency(p, p2, p3);
    }
  }
  inline double arc(const Po &a, const Po &b) {
    double alpha = acos(cos(dist(a, o), dist(b, o), dist(a, b)));
    if (det(o, a, b) < 0) alpha = 2 * PI - alpha;
    return alpha * r;
  }
};
struct Triangle {
  Po A, B, C;
  double a, b, c;
  double alpha, beta, theta;
  double r, R;
  double S, P;
  Po I, G, O, H;
  void init() {
    a = dist(B, C), b = dist(a, c), c = dist(a, b);
    alpha = acos(cos(b, c, a)), beta = acos(cos(a, c, b)),
    theta = acos(cos(a, b, c));
    P = a + b + c;
    double s = P / 2;
    S = sqrt(s * (s - a) * (s - b) * (s - c));
    R = (a * b * c) / (4 * S), r = 2 * S / P;
    I = Po(a * A.x + b * B.x + c * C.x, a * A.y + b * B.y + c * C.y) / P;
    G = (A + B + C) / 3;
    O = getX3(A, B, C), H = getX4(A, B, C);
    assert(!sgn(dist(I, O), sqrt(R * (R - 2 * r))));
    assert(!sgn(dist(H, G), dist(O, H) * 2 / 3));
  }
  void input() {
    A.input(), B.input(), C.input();
    init();
  }
};
double getArea(vector<Po> &P) {
  double S = 0;
  for (int i = 0; i < int(int((P).size())); ++i) S += det(P[i], P[i + 1]);
  return S;
}
vector<Po> getConvexHull(vector<Po> &P) {
  int n = int((P).size());
  if (n <= 3) return P;
  SRT(P);
  vector<Po> C;
  C.resize(n + 9);
  int nn = -1;
  for (int i = 0; i < int(n); ++i) {
    while (nn > 0 && dett(C[nn - 1], C[nn], P[i]) <= 0) --nn;
    C[++nn] = P[i];
  }
  int _nn = nn;
  for (int i = int(n - 1 - 1); i >= int(0); --i) {
    while (nn > _nn && dett(C[nn - 1], C[nn], P[i]) <= 0) --nn;
    C[++nn] = P[i];
  }
  C.resize(nn + 1);
  return C;
}
Circle getMinimalCoverCircle(vector<Po> &P) {
  random_shuffle(P.begin(), P.end());
  int n = int((P).size());
  Circle C(P[0]);
  for (int i = int(1); i < int(n); ++i)
    if (!~C.sgn(P[i])) {
      C = Circle(P[i]);
      for (int j = 0; j < int(i); ++j)
        if (!~C.sgn(P[j])) {
          C = Circle(P[i], P[j]);
          for (int k = 0; k < int(j); ++k)
            if (!~C.sgn(P[k])) {
              C = Circle(P[i], P[j], P[k]);
            }
        }
    }
  return C;
}
struct Polygon {
  vector<Po> P;
  void input();
};
inline bool equal(const pair<double, double> &lhs, const Seg &rhs) {
  double k, b;
  rhs.getEquation(k, b);
  return !sgn(k, lhs.first) && !sgn(b, lhs.second);
}
double getUnion(vector<Polygon> &P, vector<Seg> &S) {
  vector<pair<double, double> > L;
  for (__typeof(S.begin()) Si = S.begin(); Si != S.end(); ++Si) {
    double k, b;
    Si->getEquation(k, b);
    L.push_back(make_pair(k, b));
  }
  UNQ(L);
  double res = 0;
  for (__typeof(L.begin()) Li = L.begin(); Li != L.end(); ++Li) {
    vector<pair<double, int> > I;
    Line l0(0, Li->second, 1, Li->first + Li->second);
    for (__typeof(P.begin()) Pi = P.begin(); Pi != P.end(); ++Pi) {
      int i;
      for (i = int(1); i < int(int((Pi->P).size())); ++i)
        if (equal(*Li, Seg(Pi->P[i - 1], Pi->P[i]))) break;
      if (i != int((Pi->P).size())) continue;
      vector<Po> cut;
      for (i = int(1); i < int(int((Pi->P).size())); ++i) {
        Seg l1(Pi->P[i - 1], Pi->P[i]);
        if (!dett(l0, l1)) continue;
        Po p = l0 * l1;
        if (~l1.sgn(p)) cut.push_back(p);
      }
      UNQ(cut);
      if (int((cut).size()) == 2) {
        I.push_back(make_pair(cut[0].x, 1));
        I.push_back(make_pair(cut[1].x, -1));
      }
    }
    for (__typeof(S.begin()) Si = S.begin(); Si != S.end(); ++Si)
      if (equal(*Li, *Si)) {
        I.push_back(make_pair(min(Si->a.x, Si->b.x), 2));
        I.push_back(make_pair(max(Si->a.x, Si->b.x), -2));
      }
    SRT(I);
    int c0 = 0, c1 = 0;
    for (int i = 0; i < int(int((I).size())); ++i) {
      if (!c0 && c1)
        res += ((Li->first * I[i - 1].first + Li->second) +
                (Li->first * I[i].first + Li->second)) *
               (I[i].first - I[i - 1].first);
      if (abs(I[i].second) == 1)
        c0 += I[i].second;
      else
        c1 += I[i].second;
    }
  }
  return res;
}
double getUnion(vector<Polygon> &P) {
  vector<Seg> up, down;
  for (__typeof(P.begin()) it = P.begin(); it != P.end(); ++it) {
    for (int i = int(1); i < int(int((it->P).size())); ++i) {
      Seg s(it->P[i - 1], it->P[i]);
      int t = sgn(s.a.x, s.b.x);
      if (t > 0)
        up.push_back(s);
      else if (t < 0)
        down.push_back(s);
    }
  }
  return getUnion(P, up) - getUnion(P, down);
}
}  // namespace CG
using namespace CG;
template <class T>
inline T &RD(T &x) {
  char c;
  for (c = getchar(); c < '0'; c = getchar())
    ;
  x = c - '0';
  for (c = getchar(); '0' <= c && c <= '9'; c = getchar()) x = x * 10 + c - '0';
  return x;
}
inline double &RF(double &x) {
  x = RDD();
  return x;
}
inline char *RS(char *s) {
  scanf("%s", s);
  return s;
}
long long last_ans;
int Case;
template <class T>
inline void OT(const T &x) {
  cout << x << endl;
}
const int N = 509;
vector<Polygon> P;
int n;
double sum_area;
void Polygon::input() {
  P.resize(4);
  for (int i = 0; i < int(4); ++i) P[i].input();
  P = getConvexHull(P);
  sum_area += getArea(P);
}
int main() {
  P.resize(RD(n));
  for (int i = 0; i < int(n); ++i) P[i].input();
  printf("%.10f\n", sum_area / getUnion(P));
}