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>
using namespace std;
template <class T>
ostream &operator<<(ostream &out, const vector<T> &data) {
  out << "[";
  for (int i = 0; i < data.size(); ++i)
    out << data[i] << (i == data.size() - 1 ? "" : ",");
  out << "]";
  return out;
}
template <class T>
ostream &operator<<(ostream &out, const set<T> &s) {
  out << "{";
  for (typename set<T>::iterator itr = s.begin(); itr != s.end(); ++itr)
    out << *itr << " ";
  out << "}";
  return out;
}
template <class T>
ostream &operator<<(ostream &out, const multiset<T> &s) {
  out << "{";
  for (typename multiset<T>::iterator itr = s.begin(); itr != s.end(); ++itr)
    out << *itr << " ";
  out << "}";
  return out;
}
template <class T1, class T2>
ostream &operator<<(ostream &out, const pair<T1, T2> &p) {
  out << "(" << p.first << "," << p.second << ")";
  return out;
}
template <class T1, class T2>
ostream &operator<<(ostream &out, const map<T1, T2> &m) {
  for (typename map<T1, T2>::const_iterator itr = m.begin(); itr != m.end();
       ++itr)
    out << itr->first << "->" << itr->second << " ";
  return out;
}
const double eps = 1e-6;
const double eps_arc = 1e-10;
const double pi = acos(-1.0);
const double INF = 1e20;
inline int sign(double d) { return d < -eps ? -1 : d > eps; }
inline double sqr(double x) { return x * x; }
struct Point {
  int id;
  double x, y;
  Point() {
    x = 0.0;
    y = 0.0;
  }
  Point(double nx, double ny) : x(nx), y(ny) {}
  Point turnLeft() const { return Point(-y, x); }
  Point turnRight() const { return Point(y, -x); }
  Point rotate(double ang) const {
    return Point(x * cos(ang) - y * sin(ang), x * sin(ang) + y * cos(ang));
  }
  inline double length() { return sqrt(x * x + y * y); }
  void normalize() {
    double r = length();
    if (sign(r) != 0) x /= r, y /= r;
  }
  inline bool equal(const Point &other) const {
    return sign(x - other.x) == 0 && sign(y - other.y) == 0;
  }
  friend ostream &operator<<(ostream &out, const Point &point) {
    out << "(" << point.x << "," << point.y << ")";
    return out;
  }
  friend istream &operator>>(istream &in, Point &point) {
    in >> point.x >> point.y;
    return in;
  }
};
bool comPointByX(const Point &a, const Point &b) { return a.x < b.x; }
bool comPointEqual(const Point &a, const Point &b) { return a.equal(b); }
inline Point operator+(const Point &a, const Point &b) {
  return Point(a.x + b.x, a.y + b.y);
}
inline Point operator-(const Point &a, const Point &b) {
  return Point(a.x - b.x, a.y - b.y);
}
inline Point operator*(const Point &a, double d) {
  return Point(a.x * d, a.y * d);
}
inline Point operator/(const Point &a, double d) {
  if (sign(d) == 0) return Point();
  return Point(a.x / d, a.y / d);
}
inline bool operator==(const Point &a, const Point &b) {
  return a.x == b.x && a.y == b.y;
}
inline bool operator!=(const Point &a, const Point &b) {
  return a.x != b.x || a.y != b.y;
}
inline double dist(const Point &a, const Point &b) {
  return sqrt(sqr(a.x - b.x) + sqr(a.y - b.y));
}
inline double sqrdist(const Point &a, const Point &b) {
  return sqr(a.x - b.x) + sqr(a.y - b.y);
}
inline double operator^(const Point &a, const Point &b) {
  return a.x * b.y - a.y * b.x;
}
inline double cross(const Point &p, const Point &a, const Point &b) {
  return (a - p) ^ (b - p);
}
inline double operator*(const Point &a, const Point &b) {
  return a.x * b.x + a.y * b.y;
}
inline double dot(const Point &p, const Point &a, const Point &b) {
  return (a - p) * (b - p);
}
inline double segDegree(const Point &p, const Point &a, const Point &b) {
  double d = dot(p, a, b);
  double cosd = d / dist(a, p) / dist(b, p);
  if (cosd > 1.0) cosd = 1.0;
  if (cosd < -1.0) cosd = -1.0;
  return acos(cosd);
}
inline double segDegree(double a, double b, double c) {
  double ret = a * a + b * b - c * c;
  ret = ret / a / b / 2;
  if (ret > 1.0) ret = 1.0;
  if (ret < -1.0) ret = -1.0;
  return acos(ret);
}
inline double triangleArea(double a, double b, double c) {
  double p = (a + b + c) / 2;
  return sqrt(p * (p - a) * (p - b) * (p - c));
}
inline bool onSeg(const Point &p, const Point &a, const Point &b) {
  return (sign(cross(p, a, b)) == 0 && sign(dot(p, a, b)) <= 0);
}
inline bool onRay(const Point &p, const Point &a, const Point &b) {
  return (sign(cross(p, a, b)) == 0 && sign(dot(a, p, b)) >= 0);
}
inline bool onLine(const Point &p, const Point &a, const Point &b) {
  return sign(cross(p, a, b)) == 0;
}
pair<Point, Point> onLine(double A, double B, double C) {
  if (sign(A) == 0) return make_pair(Point(0, -C / B), Point(1, -C / B));
  if (sign(B) == 0) return make_pair(Point(-C / A, 0), Point(-C / A, 1));
  if (fabs(A + B + C) < eps)
    return make_pair(Point(-(C + B) / A, 1), Point(2, -(C + A * 2) / B));
  return make_pair(Point(-(C + B) / A, 1), Point(1, -(C + A) / B));
}
vector<Point> interLine(const Point &a, const Point &b, const Point &c,
                        const Point &d) {
  vector<Point> inters;
  double u = cross(a, c, b), v = cross(a, b, d);
  if (sign(u + v) == 0) return inters;
  Point p = (c * v + d * u) / (u + v);
  inters.push_back(p);
  return inters;
}
vector<Point> interSeg(const Point &a, const Point &b, const Point &c,
                       const Point &d) {
  vector<Point> inters = interLine(a, b, c, d);
  if (inters.size() == 0) return inters;
  const Point &p = inters[0];
  if (onSeg(p, a, b) && onSeg(p, c, d))
    return inters;
  else {
    inters.clear();
    return inters;
  }
}
pair<Point, Point> getVerticalEquallySegment(const Point &a, const Point &b) {
  Point mid = (a + b) / 2;
  Point dir = mid - a;
  dir = dir.turnLeft();
  Point begin = mid - dir;
  Point end = mid + dir;
  return make_pair(begin, end);
}
Point getMinimumDistPointOnLine(const Point &a, const Point &b,
                                const Point &p) {
  if (onLine(p, a, b)) return p;
  pair<Point, Point> vertical = getVerticalEquallySegment(a, b);
  const Point &q = p + (vertical.second - vertical.first);
  vector<Point> inter = interLine(a, b, p, q);
  return inter[0];
}
Point getMinimumDistPointOnSeg(const Point &a, const Point &b, const Point &p) {
  Point q = getMinimumDistPointOnLine(a, b, p);
  if (onSeg(q, a, b)) return q;
  if (dist(a, p) < dist(b, p))
    return a;
  else
    return b;
}
Point getMinimumDistPointOnRay(const Point &a, const Point &b, const Point &p) {
  Point q = getMinimumDistPointOnLine(a, b, p);
  if (onRay(q, a, b)) return q;
  if (dist(a, p) < dist(b, p))
    return a;
  else
    return b;
}
Point getReflectionPointByLine(const Point &a, const Point &b, const Point &p) {
  Point q = getMinimumDistPointOnLine(a, b, p);
  return q * 2 - p;
}
vector<Point> interCir(const Point &a, const Point &b, double r1, double r2) {
  vector<Point> ret;
  double d = dist(a, b), d1 = ((sqr(r1) - sqr(r2)) / d + d) / 2;
  if (sign(r1 + r2 - d) < 0 || sign(abs(r1 - r2) - d) > 0) return ret;
  Point mid = a + ((b - a) / d) * d1;
  if (sign(r1 + r2 - d) == 0) {
    ret.push_back(mid);
    return ret;
  }
  Point incr = (b - a).turnLeft() / d * sqrt(sqr(r1) - sqr(d1));
  ret.push_back(mid - incr);
  ret.push_back(mid + incr);
  return ret;
}
double interCirArea(Point a, Point b, double ra, double rb) {
  double d, dA, dB;
  d = dist(a, b);
  if ((d < eps) || (d + ra <= rb) || (d + rb <= ra))
    return sqr((rb < ra) ? rb : ra) * pi;
  if (d >= ra + rb) return 0;
  dA = (sqr(d) + sqr(ra) - sqr(rb)) / d / 2;
  dB = d - dA;
  return sqr(ra) * acos(dA / ra) - dA * sqrt(sqr(ra) - sqr(dA)) +
         sqr(rb) * acos(dB / rb) - dB * sqrt(sqr(rb) - sqr(dB));
}
vector<Point> interLineCir(const Point &o, double r, const Point &a,
                           const Point &b) {
  vector<Point> ret;
  double d = dist(a, b), h = fabs(cross(a, b, o)) / d;
  if (sign(r - h) < 0) return ret;
  double d1 = ((sqr(dist(o, a)) - sqr(dist(o, b))) / d + d) / 2;
  Point mid = a + (b - a) / d * d1;
  if (sign(r - h) == 0) {
    ret.push_back(mid);
    return ret;
  }
  Point incr = (b - a) / d * sqrt(sqr(r) - sqr(h));
  ret.push_back(mid - incr);
  ret.push_back(mid + incr);
  return ret;
}
vector<Point> interSegCir(const Point &o, double r, const Point &a,
                          const Point &b) {
  vector<Point> temp = interLineCir(o, r, a, b);
  vector<Point> ret;
  for (int i = 0; i < temp.size(); ++i)
    if (onSeg(temp[i], a, b)) ret.push_back(temp[i]);
  return ret;
}
vector<Point> tangentCirPoint(const Point &o, double r, const Point &a) {
  vector<Point> ret;
  double d = dist(a, o);
  if (sign(d - r) < 0) return ret;
  if (sign(r - d) == 0) {
    ret.push_back(a);
    return ret;
  }
  return interCir(o, a, r, sqrt(sqr(d) - sqr(r)));
}
inline bool inCircle(const Point &p, const pair<Point, double> &circle) {
  double dis = dist(p, circle.first);
  return sign(dis - circle.second) <= 0;
}
double distOnCircle(const Point &a, const Point &b, const Point &o, double r) {
  double costheta = (a - o) * (b - o) / r / r;
  double theta = acos(costheta);
  return r * theta;
}
pair<Point, double> minCoverCircle(const Point &a, const Point &b,
                                   const Point &c) {
  if (a.equal(b)) return make_pair((b + c) / 2, dist(b, c) / 2);
  if (b.equal(c)) return make_pair((c + a) / 2, dist(c, a) / 2);
  if (c.equal(a)) return make_pair((a + b) / 2, dist(a, b) / 2);
  if (onLine(a, b, c)) {
    if (onSeg(a, b, c)) return make_pair((b + c) / 2, dist(b, c) / 2);
    if (onSeg(b, a, c)) return make_pair((a + c) / 2, dist(a, c) / 2);
    return make_pair((a + b) / 2, dist(a, b) / 2);
  }
  pair<Point, double> minCircle;
  minCircle.second = INF;
  pair<Point, double> cir1 = make_pair((a + b) / 2, dist(a, b) / 2);
  pair<Point, double> cir2 = make_pair((b + c) / 2, dist(b, c) / 2);
  pair<Point, double> cir3 = make_pair((a + c) / 2, dist(a, c) / 2);
  if (inCircle(c, cir1) && cir1.second < minCircle.second) minCircle = cir1;
  if (inCircle(a, cir2) && cir2.second < minCircle.second) minCircle = cir2;
  if (inCircle(b, cir3) && cir3.second < minCircle.second) minCircle = cir3;
  Point mid1 = (a + b) / 2;
  Point mid2 = (b + c) / 2;
  Point turn1 = (b - a).turnLeft();
  Point turn2 = (c - b).turnLeft();
  turn1 = mid1 + turn1;
  turn2 = mid2 + turn2;
  vector<Point> inters = interLine(mid1, turn1, mid2, turn2);
  pair<Point, double> cir4 = make_pair(inters[0], dist(inters[0], a));
  if (cir4.second < minCircle.second) minCircle = cir4;
  return minCircle;
}
double getCircleTriangleInterArea(const Point &o, double r, const Point &a,
                                  const Point &b) {
  vector<Point> abcir = interSegCir(o, r, a, b);
  if (abcir.size() == 2 && dist(a, abcir[0]) > dist(a, abcir[1]))
    swap(abcir[0], abcir[1]);
  abcir.insert(abcir.begin(), a);
  abcir.push_back(b);
  double ret = 0;
  for (int i = 0; i < abcir.size() - 1; ++i) {
    Point &t1 = abcir[i];
    Point &t2 = abcir[i + 1];
    if (inCircle((t1 + t2) / 2, make_pair(o, r)))
      ret += fabs(cross(o, t1, t2) / 2);
    else
      ret += segDegree(o, t1, t2) * r * r * 0.5;
  }
  return ret;
}
class Polygon {
 public:
  vector<Point> pt;
  inline void clear() { pt.clear(); }
  inline int size() const { return (int)pt.size(); }
  inline void addPoint(Point a) { pt.push_back(a); }
  inline void removePoint() { pt.pop_back(); }
  inline Point &operator[](int offset) { return pt[offset]; }
  inline void getSeg(int offset, Point &a, Point &b) {
    a = pt[offset];
    b = pt[(offset + 1) % pt.size()];
  }
  int inside(const Point &p) {
    int N = (int)pt.size();
    bool positiveSign = false;
    bool negativeSign = false;
    for (int i = 0; i < N; ++i) {
      Point &now = pt[i];
      Point &next = pt[(i + 1) % N];
      Point t1 = next - now;
      Point t2 = p - next;
      int s = sign(t1 ^ t2);
      if (s == 0) {
        if (onSeg(p, now, next))
          return 0;
        else
          return -1;
      }
      if (s > 0) positiveSign = true;
      if (s < 0) negativeSign = true;
    }
    if (positiveSign && negativeSign)
      return -1;
    else
      return 1;
  }
  double interCirArea(const Point &o, double r) {
    int N = (int)pt.size();
    double ret = 0;
    for (int i = 0; i < N; ++i) {
      Point &now = pt[i];
      Point &next = pt[(i + 1) % N];
      double area = getCircleTriangleInterArea(o, r, now, next);
      if (cross(now, next, o) >= 0)
        ret += area;
      else
        ret -= area;
    }
    return ret;
  }
  int interCircle(const Point &o, double r, vector<Point> &inters) {
    inters.clear();
    bool ok = true;
    for (int i = 0; i < pt.size(); ++i)
      if (!inCircle(pt[i], make_pair(o, r))) ok = false;
    if (ok) return 1;
    if (inside(o) == 1) {
      double mindis = 1e20;
      for (int i = 0; i < pt.size(); ++i) {
        Point a = pt[i];
        Point b = pt[(i + 1) % pt.size()];
        Point p = getMinimumDistPointOnSeg(a, b, o);
        mindis = min(mindis, dist(p, o));
      }
      if (mindis >= r) return 2;
    }
    for (int i = 0; i < pt.size(); ++i) {
      Point a = pt[i];
      Point b = pt[(i + 1) % pt.size()];
      vector<Point> ps = interSegCir(o, r, a, b);
      inters.insert(inters.end(), ps.begin(), ps.end());
    }
    return inters.size() > 0 ? 3 : 4;
  }
  Point getMinDistPointInPolygon(const Point &p) {
    if (inside(p) >= 0) return p;
    int N = (int)pt.size();
    double minDis = INF;
    Point ret;
    for (int i = 0; i < N; ++i) {
      Point &a = pt[i];
      Point &b = pt[(i + 1) % N];
      Point nowMin = getMinimumDistPointOnSeg(a, b, p);
      double nowDis = dist(nowMin, p);
      if (nowDis < minDis) minDis = nowDis, ret = nowMin;
    }
    return ret;
  }
  Polygon cut(const Point &a, const Point &b) {
    Polygon newPoly;
    Point temp;
    for (unsigned int i = 0; i < pt.size(); i++) {
      Point &nowP = pt[i];
      Point &nextP = pt[(i + 1) % pt.size()];
      if (sign(cross(a, b, nowP)) <= 0) newPoly.addPoint(nowP);
      if (sign(cross(a, b, nowP)) * sign(cross(a, b, nextP)) < 0) {
        vector<Point> inters = interLine(nowP, nextP, a, b);
        if (inters.size() > 0) newPoly.addPoint(inters[0]);
      }
    }
    return newPoly;
  }
  vector<Point> polyInterLine(const Point &a, const Point &b) {
    int N = (int)pt.size();
    vector<Point> ret;
    Point temp;
    for (int i = 0; i < N; ++i) {
      Point &now = pt[i];
      Point &next = pt[(i + 1) % N];
      if (sign(cross(a, b, now)) * sign(cross(a, b, next)) <= 0) {
        vector<Point> inters = interLine(a, b, now, next);
        if (inters.size() > 0) ret.push_back(inters[0]);
      }
    }
    return ret;
  }
  double area() {
    int size = this->size();
    if (size <= 2) return 0.0;
    addPoint(this->pt[0]);
    double ans = 0;
    for (int i = 0; i < size; ++i) ans += (pt[i] ^ pt[i + 1]);
    removePoint();
    return fabs(ans / 2);
  }
  double length() {
    int size = this->size();
    addPoint(pt[0]);
    double ans = 0;
    for (int i = 0; i < size; ++i) ans += dist(pt[i], pt[i + 1]);
    removePoint();
    return ans;
  }
  pair<Point, Point> getDiameter() {
    if (this->size() == 0) return make_pair(Point(0, 0), Point(0, 0));
    if (this->size() == 1) return make_pair(pt[0], pt[0]);
    if (this->size() == 2) return make_pair(pt[0], pt[1]);
    pair<Point, Point> answer;
    double diameter = 0.0;
    for (unsigned int i = 0; i < pt.size(); ++i)
      for (unsigned int j = i + 1; j < pt.size(); ++j) {
        double now = sqrdist(pt[i], pt[j]);
        if (now > diameter) {
          diameter = now;
          answer = make_pair(pt[i], pt[j]);
        }
      }
    return answer;
  }
  pair<Point, double> getMinCoverCircle() {
    vector<Point> &points = pt;
    if (points.size() == 0) return make_pair(Point(0, 0), 0);
    if (points.size() == 1) return make_pair(points[0], 0);
    if (points.size() == 2)
      return make_pair((points[0] + points[1]) / 2,
                       dist(points[0], points[1]) / 2);
    Point a = points[0];
    Point b = points[1];
    Point c = points[2];
    pair<Point, double> nowCircle = minCoverCircle(a, b, c);
    while (true) {
      bool found = false;
      double maxDis = nowCircle.second;
      Point maxDisPoint;
      for (unsigned int i = 0; i < points.size(); ++i) {
        double dis = dist(points[i], nowCircle.first);
        if (sign(dis - maxDis) > 0) {
          maxDis = dis;
          maxDisPoint = points[i];
          found = true;
        }
      }
      if (!found) break;
      Point d = maxDisPoint;
      Point newa, newb, newc;
      pair<Point, double> cir1 = minCoverCircle(a, b, d);
      pair<Point, double> cir2 = minCoverCircle(a, c, d);
      pair<Point, double> cir3 = minCoverCircle(b, c, d);
      pair<Point, double> minCircle;
      minCircle.second = INF;
      if (inCircle(c, cir1) && cir1.second < minCircle.second) {
        minCircle = cir1;
        c = d;
      } else {
        if (inCircle(b, cir2) && cir2.second < minCircle.second) {
          minCircle = cir2;
          b = d;
        } else {
          if (inCircle(a, cir3) && cir3.second < minCircle.second) {
            minCircle = cir3;
            a = d;
          }
        }
      }
      nowCircle = minCircle;
    }
    return nowCircle;
  }
  friend ostream &operator<<(ostream &out, const Polygon &poly) {
    int size = poly.size();
    for (int i = 0; i < size; ++i) out << poly.pt[i] << "\t";
    return out;
  }
};
bool comPs(const pair<Point, int> &a, const pair<Point, int> &b) {
  int s = sign(a.first.x - b.first.x);
  if (s < 0) return true;
  if (s > 0) return false;
  return a.second < b.second;
}
double unionArea(vector<Polygon> &polys) {
  double ans = 0;
  int N = (int)polys.size();
  if (N == 0) return ans;
  vector<pair<double, double> > lines;
  for (int i = 0; i < N; ++i)
    for (int j = 0; j < polys[i].size(); ++j) {
      Point a, b;
      polys[i].getSeg(j, a, b);
      if (fabs(a.x - b.x) < eps) continue;
      double deg = atan2(b.y - a.y, b.x - a.x);
      double bb = a.y - (b.y - a.y) * a.x / (b.x - a.x);
      bool close = false;
      for (int k = 0; k < lines.size(); ++k)
        if (fabs(lines[k].first - deg) < eps_arc &&
            fabs(lines[k].second - bb) < eps)
          close = true;
      if (close) continue;
      lines.push_back(make_pair(deg, bb));
      vector<pair<Point, int> > ps;
      for (int k = 0; k < N; ++k) {
        bool isPar = false;
        for (int l = 0; l < polys[k].size(); ++l) {
          Point c, d;
          polys[k].getSeg(l, c, d);
          if (fabs(c.x - d.x) < eps) continue;
          if (onLine(c, a, b) && onLine(d, a, b)) {
            int dir = (c.x < d.x) ? 2 : 1;
            if (c.x > d.x) swap(c, d);
            ps.push_back(make_pair(c, dir * 2));
            ps.push_back(make_pair(d, dir * 2 + 1));
            isPar = true;
            break;
          }
        }
        if (isPar) continue;
        vector<Point> inters;
        for (int l = 0; l < polys[k].size(); ++l) {
          Point c, d;
          polys[k].getSeg(l, c, d);
          vector<Point> t = interLine(a, b, c, d);
          for (int z = 0; z < t.size(); ++z)
            if (onSeg(t[z], c, d)) inters.push_back(t[z]);
        }
        sort(inters.begin(), inters.end(), comPointByX);
        inters.resize(unique(inters.begin(), inters.end(), comPointEqual) -
                      inters.begin());
        if (inters.size() >= 2) {
          ps.push_back(make_pair(inters.front(), 0));
          ps.push_back(make_pair(inters.back(), 1));
        }
      }
      sort(ps.begin(), ps.end(), comPs);
      int cntPosi = 0, cntNega = 0;
      int cntIn = 0;
      for (int k = 0; k < ps.size(); ++k) {
        double x2 = ps[k].first.x;
        double y2 = ps[k].first.y;
        double x1 = 0, y1 = 0;
        if (k > 0) {
          x1 = ps[k - 1].first.x;
          y1 = ps[k - 1].first.y;
        }
        double area = (x2 - x1) * (y2 + y1) / 2;
        if (cntPosi > 0 && cntNega == 0 && x2 - x1 > eps && cntIn == 0)
          ans += area;
        if (cntPosi == 0 && cntNega > 0 && x2 - x1 > eps && cntIn == 0)
          ans -= area;
        int id = ps[k].second;
        if (id == 2) cntPosi++;
        if (id == 4) cntNega++;
        if (id == 0) cntIn++;
        if (id == 3) cntPosi--;
        if (id == 5) cntNega--;
        if (id == 1) cntIn--;
      }
    }
  return ans;
}
struct ConvexHull {
  static inline bool cmp(const Point &a, const Point &b) {
    return a.y < b.y || (a.y == b.y && a.x < b.x);
  }
  static Polygon convexHull(const vector<Point> &points,
                            bool needInnerEdgePoint = false) {
    vector<Point> p(points.begin(), points.end());
    vector<int> stack(p.size() + 1);
    Polygon poly;
    poly.clear();
    if (p.size() == 0) return poly;
    if (p.size() == 1) {
      poly.addPoint(points[0]);
      return poly;
    }
    sort(p.begin(), p.end(), ConvexHull::cmp);
    int threshold = 0;
    if (needInnerEdgePoint) threshold = 1;
    int N = (int)p.size();
    int top = -1;
    stack[++top] = 0;
    stack[++top] = 1;
    for (int i = 2; i < N; i++) {
      while (top >= 1 &&
             sign(cross(p[stack[top - 1]], p[i], p[stack[top]])) >= threshold)
        top--;
      stack[++top] = i;
    }
    int temp_top = top;
    stack[++top] = N - 2;
    for (int i = N - 3; i >= 0; i--) {
      while (top >= temp_top + 1 &&
             sign(cross(p[stack[top - 1]], p[i], p[stack[top]])) >= threshold)
        top--;
      stack[++top] = i;
    }
    for (int i = 0; i < top; ++i) poly.addPoint(p[stack[i]]);
    return poly;
  }
};
class HalfPlanes {
 public:
  Polygon poly;
  HalfPlanes(double maxRange) {
    poly.addPoint(Point(-maxRange, -maxRange));
    poly.addPoint(Point(maxRange, -maxRange));
    poly.addPoint(Point(maxRange, maxRange));
    poly.addPoint(Point(-maxRange, maxRange));
  }
  void intersect(const Point &a, const Point &b) { poly = poly.cut(a, b); }
  void intersect(double A, double B, double C) {
    pair<Point, Point> ab = onLine(A, B, C);
    pair<Point, Point> cd = getVerticalEquallySegment(ab.first, ab.second);
    Point a = ab.first, b = ab.second, c = cd.first, d = cd.second;
    double vc = A * c.x + B * c.y + C;
    if (vc > 0) {
      if (sign(cross(a, b, c)) > 0) swap(a, b);
    } else {
      if (sign(cross(a, b, d)) > 0) swap(a, b);
    }
    poly = poly.cut(a, b);
  }
  void intersect(const Point &a, const Point &b, const Point &c) {
    if (sign(cross(a, b, c)) <= 0)
      poly = poly.cut(a, b);
    else
      poly = poly.cut(b, a);
  }
};
class Voronoy {
 public:
  vector<Point> ps;
  vector<HalfPlanes> planes;
  Voronoy(vector<Point> &points, double maxRange) {
    int N = (int)points.size();
    ps = points;
    planes.resize(N, HalfPlanes(maxRange));
    for (int i = 0; i < N; ++i)
      for (int j = i + 1; j < N; ++j) {
        pair<Point, Point> v = getVerticalEquallySegment(ps[i], ps[j]);
        planes[i].intersect(v.first, v.second, ps[i]);
        planes[j].intersect(v.first, v.second, ps[j]);
      }
  }
};
struct Point3D {
  double x, y, z;
  Point3D() {}
  Point3D(double xx, double yy, double zz) {
    x = xx;
    y = yy;
    z = zz;
  }
  double len() { return sqrt(x * x + y * y + z * z); }
};
Point3D operator+(const Point3D &a, const Point3D &b) {
  return Point3D(a.x + b.x, a.y + b.y, a.z + b.z);
}
Point3D operator-(const Point3D &a, const Point3D &b) {
  return Point3D(a.x - b.x, a.y - b.y, a.z - b.z);
}
double dist(const Point3D &a, const Point3D &b) {
  return sqrt(sqr(a.x - b.x) + sqr(a.y - b.y) + sqr(a.z - b.z));
}
double dot(const Point3D &a, const Point3D &b) {
  return a.x * b.x + a.y * b.y + a.z * b.z;
}
Point3D cross(const Point3D &u, const Point3D &v) {
  Point3D ret;
  ret.x = u.y * v.z - v.y * u.z;
  ret.y = u.z * v.x - u.x * v.z;
  ret.z = u.x * v.y - u.y * v.x;
  return ret;
}
Point3D planeVector(const Point3D &a, const Point3D &b, const Point3D &c) {
  return cross(a - b, b - c);
}
double distToPlane(const Point3D &p, const Point3D &s1, const Point3D &s2,
                   const Point3D &s3) {
  Point3D plane = planeVector(s1, s2, s3);
  return dot(plane, p - s1) / plane.len();
}
Point ps[4];
Point a, b, c, d;
class State {
 public:
  double x, y, z;
  State operator+(const State &other) {
    State ret;
    ret.x = x + other.x;
    ret.y = y + other.y;
    ret.z = z + other.z;
    return ret;
  }
  State operator-(const State &other) {
    State ret;
    ret.x = x - other.x;
    ret.y = y - other.y;
    ret.z = z - other.z;
    return ret;
  }
  State operator*(double k) {
    State ret;
    ret.x = x * k;
    ret.y = y * k;
    ret.z = z * k;
    return ret;
  }
  friend ostream &operator<<(ostream &out, const State &state) {
    out << state.x << " " << state.y << " " << state.z;
    return out;
  }
};
double func(const State &s) {
  Point p(s.x, s.y);
  double ret = dist(Point(0, 0), p);
  ret += dist(getMinimumDistPointOnLine(c, d, p), p);
  return ret;
}
class GoldSplitSearch {
 public:
  static State findMinimum(State &begin, State &end,
                           double (*func)(const State &s)) {
    const double tou = (sqrt(5.0) - 1) / 2;
    State a = begin;
    State b = end;
    for (int k = 0; k < 200; ++k) {
      State x1 = a + (b - a) * (1 - tou);
      State x2 = a + (b - a) * tou;
      double f1 = func(x1);
      double f2 = func(x2);
      if (f1 > f2)
        a = x1;
      else
        b = x2;
    }
    return a;
  }
};
double getAns(Point aa, Point bb, Point cc, Point dd) {
  c = cc;
  d = dd;
  double scale = 100000 / (bb - aa).length();
  Point na = (aa - bb) * scale + bb;
  Point nb = (bb - aa) * scale + aa;
  State begin;
  begin.x = na.x;
  begin.y = na.y;
  State end;
  end.x = nb.x;
  end.y = nb.y;
  State s = GoldSplitSearch::findMinimum(begin, end, func);
  return func(s);
}
int N;
vector<Polygon> polys;
void init() {
  double ans = 0;
  cin >> N;
  polys.clear();
  for (int i = 0; i < N; ++i) {
    vector<Point> ps(4);
    for (int j = 0; j < 4; ++j) cin >> ps[j];
    Polygon poly = ConvexHull::convexHull(ps);
    polys.push_back(poly);
    ans += poly.area();
  }
  ans = ans / (unionArea(polys));
  printf("%.10f\n", ans);
}
void york() {}
int main() {
  init();
  york();
  return 0;
}