Problem: You are given two rectangles on a plane. The centers of both rectangles are located in the origin of coordinates (meaning the center of the rectangle's symmetry). The first rectangle's sides are parallel to the coordinate axes: the length of the side that is parallel to the Ox axis, equals w, the length of the side that is parallel to the Oy axis, equals h. The second rectangle can be obtained by rotating the first rectangle relative to the origin of coordinates by angle α.

<image>

Your task is to find the area of the region which belongs to both given rectangles. This region is shaded in the picture.

Input

The first line contains three integers w, h, α (1 ≤ w, h ≤ 106; 0 ≤ α ≤ 180). Angle α is given in degrees.

Output

In a single line print a real number — the area of the region which belongs to both given rectangles.

The answer will be considered correct if its relative or absolute error doesn't exceed 10 - 6.

Examples

Input

1 1 45


Output

0.828427125


Input

6 4 30


Output

19.668384925

Note

The second sample has been drawn on the picture above.

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
template <class T>
string toStr(const T &x) {
  stringstream s;
  s << x;
  return s.str();
}
template <class T>
int toInt(const T &x) {
  stringstream s;
  s << x;
  int r;
  s >> r;
  return r;
}
const double pi = acos(-1);
const double Pi2 = acos(0);
double circle_angle(double a) { return a >= 0 ? a : Pi2 + a; }
template <typename T>
struct Point {
  T x, y;
  Point() { x = y = 0; }
  Point(T X, T Y) : x(X), y(Y) {}
  T distance(const Point &p) const {
    T dx = p.x - x, dy = p.y - y;
    return sqrt(dx * dx + dy * dy);
  }
  bool operator<(const Point &p) const {
    return x < p.x || (x == p.x && y < p.y);
  }
  Point operator-(const Point &b) const { return Point(x - b.x, y - b.y); }
  bool collinear(const Point &b, const Point &c) const {
    return (b.y - y) * (c.x - x) == (c.y - y) * (b.x - x);
  }
};
struct Vector {
  double x, y;
  Vector(double X, double Y) : x(X), y(Y) {}
  Vector(const Point<double> &p) : x(p.x), y(p.y) {}
  double norm() { return sqrt(x * x + y * y); }
  double cross(const Vector &v) const { return x * v.y - y * v.x; }
  double angle(const Vector &p) const {
    return circle_angle(atan2(p.y, p.x) - atan2(y, x));
  }
  void rotate(double a) {
    double px = x, py = y;
    x = px * cos(a) - py * sin(a);
    y = px * sin(a) + py * cos(a);
  }
  double distance_line_point(Point<double> a, Point<double> p) {
    return fabs((p.x - a.x) * y - (p.y - a.y) * x) / sqrt(x * x + y * y);
  }
};
double eps = 1e-7;
struct point {
  double x, y;
  point() {}
  point(double X, double Y) : x(X), y(Y) {}
  point sub(point a) { return point(x - a.x, y - a.y); }
  point add(point a) { return point(x + a.x, y + a.y); }
  double cross(point a) { return x * a.y - y * a.x; }
  point multbyscalar(double ua) { return point(ua * x, ua * y); }
};
int n, l, w;
vector<point> initPol(double a, double b) {
  vector<point> ans(4);
  ans[0] = point(a, b);
  ans[1] = point(-a, b);
  ans[2] = point(-a, -b);
  ans[3] = point(a, -b);
  return ans;
}
point intersectionbtwlines(point &p1, point &p2, point &p3, point &p4) {
  point p2_p1 = p2.sub(p1);
  point p4_p3 = p4.sub(p3);
  double den = p2_p1.cross(p4_p3);
  if (fabs(den) < eps) return point();
  point p1_p3 = p1.sub(p3);
  double num = p4_p3.cross(p1_p3);
  double ua = num / den;
  return p2_p1.multbyscalar(ua).add(p1);
}
vector<point> sutherland_hodgman(vector<point> &line, vector<point> &poly,
                                 int flag) {
  vector<point> output;
  point S = poly[poly.size() - 1];
  for (int i = 0; i < poly.size(); i++) {
    point E = poly[i];
    double ecross = line[1].sub(line[0]).cross(E.sub(line[0]));
    double scross = line[1].sub(line[0]).cross(S.sub(line[0]));
    if (fabs(ecross) < eps)
      output.push_back(E);
    else if (ecross * flag > eps) {
      if (scross * flag < -eps) {
        double den = (E.y - S.y) * (line[1].x - line[0].x) -
                     (E.x - S.x) * (line[1].y - line[0].y);
        if (fabs(den) > eps) {
          double num =
              (E.x - S.x) * (line[0].y - S.y) - (E.y - S.y) * (line[0].x - S.x);
          num /= den;
          output.push_back(point((line[1].x - line[0].x) * num + line[0].x,
                                 (line[1].y - line[0].y) * num + line[0].y));
        }
      }
      output.push_back(E);
    } else if (scross * flag > eps) {
      double den = (E.y - S.y) * (line[1].x - line[0].x) -
                   (E.x - S.x) * (line[1].y - line[0].y);
      if (fabs(den) > eps) {
        double num =
            (E.x - S.x) * (line[0].y - S.y) - (E.y - S.y) * (line[0].x - S.x);
        num /= den;
        output.push_back(point((line[1].x - line[0].x) * num + line[0].x,
                               (line[1].y - line[0].y) * num + line[0].y));
      }
    }
    S = E;
  }
  return output;
}
vector<vector<point> > bisection(vector<point> &line, vector<point> &poly) {
  vector<point> uno = sutherland_hodgman(line, poly, 1);
  vector<point> dos = sutherland_hodgman(line, poly, -1);
  int amount = (uno.size() > 2) ? 1 : 0;
  amount += (dos.size() > 2) ? 1 : 0;
  vector<vector<point> > ret(amount);
  int index = 0;
  if (uno.size() > 2) ret[index++] = uno;
  if (dos.size() > 2) ret[index++] = dos;
  return ret;
}
double PolygonArea(const vector<point> &p) {
  double r = 0.0;
  for (int i = 0; i < p.size(); ++i) {
    int j = (i + 1) % p.size();
    r += p[i].x * p[j].y - p[j].x * p[i].y;
  }
  return fabs(r / 2.0);
}
int main() {
  double h, w, n;
  while (cin >> h >> w >> n) {
    n = n * pi / 180.0;
    Vector a(w / 2.0, h / 2.0);
    Vector b(-w / 2.0, h / 2.0);
    Vector c(-w / 2.0, -h / 2.0);
    Vector d(w / 2.0, -h / 2.0);
    vector<point> poly = initPol(w / 2.0, h / 2.0);
    a.rotate(n);
    b.rotate(n);
    c.rotate(n);
    d.rotate(n);
    vector<vector<point> > ans;
    ans.push_back(poly);
    vector<point> line(2);
    line[0] = point(a.x, a.y);
    line[1] = point(b.x, b.y);
    vector<vector<point> > tmp;
    for (typeof(ans).begin() pol = (ans).begin(); pol != (ans).end(); pol++) {
      vector<vector<point> > result = bisection(line, (*pol));
      for (int j = 0; j < result.size(); ++j) tmp.push_back(result[j]);
    }
    ans = tmp;
    line[0] = point(b.x, b.y);
    line[1] = point(c.x, c.y);
    tmp.clear();
    for (typeof(ans).begin() pol = (ans).begin(); pol != (ans).end(); pol++) {
      vector<vector<point> > result = bisection(line, (*pol));
      for (int j = 0; j < result.size(); ++j) tmp.push_back(result[j]);
    }
    ans = tmp;
    line[0] = point(c.x, c.y);
    line[1] = point(d.x, d.y);
    tmp.clear();
    for (typeof(ans).begin() pol = (ans).begin(); pol != (ans).end(); pol++) {
      vector<vector<point> > result = bisection(line, (*pol));
      for (int j = 0; j < result.size(); ++j) tmp.push_back(result[j]);
    }
    ans = tmp;
    line[0] = point(d.x, d.y);
    line[1] = point(a.x, a.y);
    tmp.clear();
    for (typeof(ans).begin() pol = (ans).begin(); pol != (ans).end(); pol++) {
      vector<vector<point> > result = bisection(line, (*pol));
      for (int j = 0; j < result.size(); ++j) tmp.push_back(result[j]);
    }
    ans = tmp;
    double mio = 0;
    mio = PolygonArea(ans[0]);
    printf("%.10lf\n", mio);
  }
  return 0;
}